EPC Issues

[dubvag]

Hey guys, I know there's a lot of information on EPC issues already and I've been researching it a bit the past few days. But I'm hoping someone can just point me in the right direction, as there seems to be many things that can lead to the EPC light coming on.

I bought the car in April and haven't really had any big issues with it yet. The EPC light did come in once back in maybe July, but it was gone after I restarted the car and never came back. Until Monday. I noticed it came on while driving home from work, I had to stop at the grocery store so I got my milk came back out to the car. When I left, the light was out again. But it came back on a little later, this time with the CEL. When I got home I plugged into the OBDII port and got the P2020 code. I cleared the code hoping it might stay away, but I knew better deep down. The EPC and CEL came back on Wednesday. Now the CEL is always on, but the EPC never comes on right away. Now EPC lights up anywhere from 5-30 minutes into my drive, but it's never on when I start the car.

Should the fact that the light isn't always on lead me to believe there is no vacuum leak? Is it likely just a bad sensor? I also haven't noticed an obvious loss in power (though I haven't really wanted to thrash on it with the EPC light being on and off). But power definitely isn't getting cut off at 3k RPM or anything like that.

I guess if anyone has some insight on the issue, good things I should check first, or any other input, it would be greatly appreciated.

Sent from my PH-1 using Audizine mobile app

[AA 954]

Hey guys, I know there's a lot of information on EPC issues already and I've been researching it a bit the past few days. But I'm hoping someone can just point me in the right direction, as there seems to be many things that can lead to the EPC light coming on.

I bought the car in April and haven't really had any big issues with it yet. The EPC light did come in once back in maybe July, but it was gone after I restarted the car and never came back. Until Monday. I noticed it came on while driving home from work, I had to stop at the grocery store so I got my milk came back out to the car. When I left, the light was out again. But it came back on a little later, this time with the CEL. When I got home I plugged into the OBDII port and got the P2020 code. I cleared the code hoping it might stay away, but I knew better deep down. The EPC and CEL came back on Wednesday. Now the CEL is always on, but the EPC never comes on right away. Now EPC lights up anywhere from 5-30 minutes into my drive, but it's never on when I start the car.

Should the fact that the light isn't always on lead me to believe there is no vacuum leak? Is it likely just a bad sensor? I also haven't noticed an obvious loss in power (though I haven't really wanted to thrash on it with the EPC light being on and off). But power definitely isn't getting cut off at 3k RPM or anything like that.

I guess if anyone has some insight on the issue, good things I should check first, or any other input, it would be greatly appreciated.

Sent from my PH-1 using Audizine mobile app

P2015 and P2020 is a code that comes up for each of the banks (1 & 2) when the values measured by each potentiometer are out of range, this will automatically come accompanied by an EPC code which in turn will limit your revs to ~7k

Potential Reasons for this:

- Needs a Carbon Clean, flap arms get stuck and do not open or close enough, basically at idle flaps in the IM will stay close until around 4k where they will open, at close or open they need to read within a range or the ecu will throw a code.

- Vacuum bypass/sensor at the front of the IM needs changing, there should be a write up somewhere or reach out to either Jonan or Pyromatic as they have changed this without removing their IM’s, PITA scale 5-6 and you need small hands

- Bad potentiometer, one you can change without removing the Intake Manifold, if its the other you will need to remove it as I recall.

- Bad actuator vacuum arms, these are at the front and underneath the manifold, hopefully its not the one that controls the right bank as they are expensive to change

- Bad linkage arm, have someone accelerate your car to above 4k and see if these move evenly, these plastic arms wear over time and break although if it was broken, I would expect you to get a code immediately after hitting 4k revs the first time.

- Vacuum leak on the hose that connects to the vacuum actuator arm bank 2

- Think I read somewhere that a bad PCV can influence on this too, no idea...

My personal experience when I had these codes is that it got fixed after performing a Carbon Clean, installing new potentiometers and changed that front IM valve bypass/sensor.

[dubvag]

P2015 and P2020 is a code that comes up for each of the banks (1 & 2) when the values measured by each potentiometer are out of range, this will automatically come accompanied by an EPC code which in turn will limit your revs to ~7k

Potential Reasons for this:

- Needs a Carbon Clean, flap arms get stuck and do not open or close enough, basically at idle flaps in the IM will stay close until around 4k where they will open, at close or open they need to read within a range or the ecu will throw a code.

- Vacuum bypass/sensor at the front of the IM needs changing, there should be a write up somewhere or reach out to either Jonan or Pyromatic as they have changed this without removing their IM’s, PITA scale 5-6 and you need small hands

- Bad potentiometer, one you can change without removing the Intake Manifold, if its the other you will need to remove it as I recall.

- Bad actuator vacuum arms, these are at the front and underneath the manifold, hopefully its not the one that controls the right bank as they are expensive to change

- Bad linkage arm, have someone accelerate your car to above 4k and see if these move evenly, these plastic arms wear over time and break although if it was broken, I would expect you to get a code immediately after hitting 4k revs the first time.

- Vacuum leak on the hose that connects to the vacuum actuator arm bank 2

- Think I read somewhere that a bad PCV can influence on this too, no idea...

My personal experience when I had these codes is that it got fixed after performing a Carbon Clean, installing new potentiometers and changed that front IM valve bypass/sensor.

Thanks AA 954, this is a lot of great information! I know if it is a bad potentiometer mine is the one that requires the manifold to be removed. If that's the case, is it worth changing both at the same time?

The car had a carbon cleaning about 10,000 miles ago, so hopefully that's not already needed again.

I'll have to look into all this more this weekend and hopefully am able to narrow it down a little more. I'll try to keep you posted!

Sent from my PH-1 using Audizine mobile app

[AA 954]

Thanks AA 954, this is a lot of great information! I know if it is a bad potentiometer mine is the one that requires the manifold to be removed. If that's the case, is it worth changing both at the same time?

The car had a carbon cleaning about 10,000 miles ago, so hopefully that's not already needed again.

I'll have to look into all this more this weekend and hopefully am able to narrow it down a little more. I'll try to keep you posted!

Sent from my PH-1 using Audizine mobile app

If you need to take the mani off again then yes change both together with the check valve thats at the bottom of the mani connected to the vacuum lines, there is also an N80 valve in the area where the valley pan is, change that too.

Whats the mileage on the car? Depending on that you might want to consider injectors and PCV if you haven’t changed those.

If you already had the CC done I would start by changing that front sensor before removing anything, you’ll need needle nose pliers and small hands lol. You take off that front engine cover and the braket that supports it so you can access that sensor, its a bit tight and there are some vacuum lines there that you need to be careful with. If that doesn’t help then you’ll need to evaluate taking the mani off

[dubvag]

If you need to take the mani off again then yes change both together with the check valve thats at the bottom of the mani connected to the vacuum lines, there is also an N80 valve in the area where the valley pan is, change that too.

Whats the mileage on the car? Depending on that you might want to consider injectors and PCV if you haven’t changed those.

If you already had the CC done I would start by changing that front sensor before removing anything, you’ll need needle nose pliers and small hands lol. You take off that front engine cover and the braket that supports it so you can access that sensor, its a bit tight and there are some vacuum lines there that you need to be careful with. If that doesn’t help then you’ll need to evaluate taking the mani off

I just hit 94,000 miles this week. I'll have to look at the records, but I think the CC was done around 83k. I'm not sure if injectors were done at that time. If I do end up taking the manifold off, is there an easy way to visually inspect the injectors? I'd probably order them either way, but if they look ok maybe save them for the next CC?

I'll try getting my hands on that front sensor to try right away. I'll see what I can do about the small hands, haha.

[AA 954]

I just hit 94,000 miles this week. I'll have to look at the records, but I think the CC was done around 83k. I'm not sure if injectors were done at that time. If I do end up taking the manifold off, is there an easy way to visually inspect the injectors? I'd probably order them either way, but if they look ok maybe save them for the next CC?

I'll try getting my hands on that front sensor to try right away. I'll see what I can do about the small hands, haha.

Injectors are a hit or miss at these mileages but the best insurance in my opinion, good thing is they are relatively cheap on FCP or Rockauto in comparison to the dealer, the clips you’ll need to source from Ebay as they are very expensive from the dealer.

I’m sure there is a way to test the injectors, supposedly if you turn the car off after its reached operating temperature and continue measuring the HPFP flow block the pressure should continue to rise indicating that there is no pressure loss from one of the injectors, no idea how to measure them individually in our cars so probably someone else can pitch in on that.

Definately start with that sensor, for reference I’ve attached a picture so you know which one it is.

IMG_2580.jpg

[dubvag]

Injectors are a hit or miss at these mileages but the best insurance in my opinion, good thing is they are relatively cheap on FCP or Rockauto in comparison to the dealer, the clips you’ll need to source from Ebay as they are very expensive from the dealer.

I’m sure there is a way to test the injectors, supposedly if you turn the car off after its reached operating temperature and continue measuring the HPFP flow block the pressure should continue to rise indicating that there is no pressure loss from one of the injectors, no idea how to measure them individually in our cars so probably someone else can pitch in on that.

Definately start with that sensor, for reference I’ve attached a picture so you know which one it is.

IMG_2580.jpg

Thanks!

This is the sensor you're referring to correct?

https://jhmotorsports.com/solenoid-f...or-b7-rs4.html

You don't have a part number do you? I can't seem to find this sensor on many websites.

[AA 954]

Thanks!

This is the sensor you're referring to correct?

https://jhmotorsports.com/solenoid-f...or-b7-rs4.html

You don't have a part number do you? I can't seem to find this sensor on many websites.

Yes thats the part, go with this one:

https://www.fcpeuro.com/products/aud...lve-037906283c

Pierburg is the OE Manufucturer, absolutely crazy that the OEM costs 70-80$ more just to carry the AUDI logo...

Pic of my old part for reference

[dubvag]

Yes thats the part, go with this one:

https://www.fcpeuro.com/products/aud...lve-037906283c

Pierburg is the OE Manufucturer, absolutely crazy that the OEM costs 70-80$ more just to carry the AUDI logo...

Pic of my old part for reference

Thanks! I did see that one on FCP Euro too, but it says it's not compatible with the RS4. False positive?

[AA 954]

Thanks! I did see that one on FCP Euro too, but it says it's not compatible with the RS4. False positive?

Seems that way as the part number is correct. Also that JHM link says its a Piersburg too. Probably shoot FCP a note just to double check

[Tkalxx]

Just wanted to chime in if you haven't already found the cause of your EPC light. I had the exact same issues when I had my EPC light (wouldn't come on at start up but after 15-20 mins of driving it would). The problem ended up being the manifold flaps, they were jammed either open or closed I can't remember exactly.

[dubvag]

Just wanted to chime in if you haven't already found the cause of your EPC light. I had the exact same issues when I had my EPC light (wouldn't come on at start up but after 15-20 mins of driving it would). The problem ended up being the manifold flaps, they were jammed either open or closed I can't remember exactly.

Thanks for the heads up. I really hope that's not the issue though, ha. You would think the light would come on right away if the flaps were stuck opened or closed wouldn't you?

Also, what did you have to do to fix that? Whole new manifold, linkage, CC?

Sent from my PH-1 using Audizine mobile app

[Tkalxx]

Thanks for the heads up. I really hope that's not the issue though, ha. You would think the light would come on right away if the flaps were stuck opened or closed wouldn't you?

Also, what did you have to do to fix that? Whole new manifold, linkage, CC?

Sent from my PH-1 using Audizine mobile app

I believe the light doesn't come on at start up because at idle and <5k rpm the flaps are closed. Now that I've had some time to think about it, mine were stuck closed and in retrospect I should've done a test to see if the EPC light would come on if I went WOT above 5k.

My car was already due for a CC at the time so I had that done by a shop to see if it would help and sure enough no more EPC light. Unfortunately, that probably isn't much help to you as you said a CC was done ~10k miles ago... I've also heard the solenoids that control the flaps for each bank sometimes go bad or they experience a vacuum leak. Post 51 of this thread gives a little detail on how to diagnose if your intake flaps are stuck close if you have access to VCDS.

[dubvag]

I believe the light doesn't come on at start up because at idle and <5k rpm the flaps are closed. Now that I've had some time to think about it, mine were stuck closed and in retrospect I should've done a test to see if the EPC light would come on if I went WOT above 5k.

My car was already due for a CC at the time so I had that done by a shop to see if it would help and sure enough no more EPC light. Unfortunately, that probably isn't much help to you as you said a CC was done ~10k miles ago... I've also heard the solenoids that control the flaps for each bank sometimes go bad or they experience a vacuum leak. Post 51 of this thread gives a little detail on how to diagnose if your intake flaps are stuck close if you have access to VCDS.

Unfortunately I don't have access to VCDS. The sensor I ordered looks like it should be arriving Wednesday. So hopefully I can get that changed out Wednesday evening after work and see where things go from there.

[AA 954]

Unfortunately I don't have access to VCDS. The sensor I ordered looks like it should be arriving Wednesday. So hopefully I can get that changed out Wednesday evening after work and see where things go from there.

I’d definately continue as you have planned, not sure if you had read this other write up?


https://www.audizine.com/forum/showt...959-P2020-code

The air intake flap if I recall has a similar sensor (if not the same) underneath the airbox to the one at the front of the Intake Manifold, someone in our group chat changed it maybe about 6 months ago and the code he was getting was as I recall P2015

[dubvag]

I’d definately continue as you have planned, not sure if you had read this other write up?


https://www.audizine.com/forum/showt...959-P2020-code

The air intake flap if I recall has a similar sensor (if not the same) underneath the airbox to the one at the front of the Intake Manifold, someone in our group chat changed it maybe about 6 months ago and the code he was getting was as I recall P2015

I had seen that post and noticed our cars have two of those sensors. Guess I'll start with this first one though.

Also, weirdly this morning on my way to work there was no CEL at all. I hadn't seen the EPC light at all since Monday morning, but the CEL had always been on. Now it's like nothing ever happened! Guess I'll wait to swap out the sensor I ordered until after the lights come back on. I'm assuming they will.

Sent from my PH-1 using Audizine mobile app

[AA 954]

I had seen that post and noticed our cars have two of those sensors. Guess I'll start with this first one though.

Also, weirdly this morning on my way to work there was no CEL at all. I hadn't seen the EPC light at all since Monday morning, but the CEL had always been on. Now it's like nothing ever happened! Guess I'll wait to swap out the sensor I ordered until after the lights come back on. I'm assuming they will.

Sent from my PH-1 using Audizine mobile app

Another cheap option I forgot to share and given that you did your CC not long ago is to use CRC’s Intake Cleaner. A few of us are testing this and have added this to our maintenance regime (every 5K miles). If the cause is a bit of carbon in the flaps making it get stuck or not opening within range, this could help (I can’t assure it but worth a try) to clean up some of the build that you might already have.

As I mentioned it’s not that expensive and easy to do:

https://www.amazon.com/dp/B00PHNQKR2..._bjKNDbRMF8RV5

[dubvag]

Another cheap option I forgot to share and given that you did your CC not long ago is to use CRC’s Intake Cleaner. A few of us are testing this and have added this to our maintenance regime (every 5K miles). If the cause is a bit of carbon in the flaps making it get stuck or not opening within range, this could help (I can’t assure it but worth a try) to clean up some of the build that you might already have.

As I mentioned it’s not that expensive and easy to do:

https://www.amazon.com/dp/B00PHNQKR2..._bjKNDbRMF8RV5

I'll have to take a look at that too. Do you spray it into the intake with the engine running? Is there a thread somewhere on this stuff?

Sent from my PH-1 using Audizine mobile app

[AA 954]

I'll have to take a look at that too. Do you spray it into the intake with the engine running? Is there a thread somewhere on this stuff?

Sent from my PH-1 using Audizine mobile app

No thread that I’m aware off, all the steps are explained on the can, the engine needs to be running at a constant 2.5 or 3k as I recall and you spray in bursts post MAF, basically loosen that MAF hose so you can spray in.

Obviously this will never substitute a carbon clean, some of us are just curious to see what it does... and technically it should remove a little bit of that loose carbon that we should have after 5K, 10K and so on after the initial clean. In any case I already decided that I will follow an every 25K miles carbon clean maintenance schedule.

[MugelloB7RS4]

No thread that I’m aware off, all the steps are explained on the can, the engine needs to be running at a constant 2.5 or 3k as I recall and you spray in bursts post MAF, basically loosen that MAF hose so you can spray in.

Obviously this will never substitute a carbon clean, some of us are just curious to see what it does... and technically it should remove a little bit of that loose carbon that we should have after 5K, 10K and so on after the initial clean. In any case I already decided that I will follow an every 25K miles carbon clean maintenance schedule.

I use something similar, but I got it from BG products. Its a little chamber that you pressurize and injects a cleaner post MAF just before throttle body. You inject it once the engine is up to full temp and you let it run at idle with bursts up to 2 or 3K then when done drive the bejesus out of the car and not long after change oil. I plan to do this on every oil change as I cleaned valves about a year and a half ago and want to see if this will help prolong the time between carbon cleans. It totally could be snake oil, but starting with clean valves I thought it would be interesting to try and see if any change is noticed.

[dubvag]

EPC and CEL came back on last Friday coming home from work. I wasn't around over the weekend so I'll plan on swapping out the sensor probably tomorrow night. I think I might try to pick up some of the intake cleaner stuff you guys were talking about too.

Sent from my PH-1 using Audizine mobile app

[dubvag]

Just got the new sensor put in tonight. Took the car for a 15 minute ride with no lights so far. We'll see if I got lucky with the easy fix!

[AA 954]

Just got the new sensor put in tonight. Took the car for a 15 minute ride with no lights so far. We'll see if I got lucky with the easy fix!

The one at the front of the mani correct? Hopefully its that so you don’t need to troubleshoot any further

[dubvag]

The one at the front of the mani correct? Hopefully its that so you don’t need to troubleshoot any further

Yup, that was the one I replaced. Keep your fingers crossed!

Sent from my PH-1 using Audizine mobile app

[dubvag]

No lights so far this weekend. I was also looking back at the CC paperwork I got with the car. Looks like I should have the 034Motorsport linkage arms in the IM. These are the hard to install arms that replace the brittle plastic ones correct?

[AA 954]

No lights so far this weekend. I was also looking back at the CC paperwork I got with the car. Looks like I should have the 034Motorsport linkage arms in the IM. These are the hard to install arms that replace the brittle plastic ones correct?

Yes, real pita to install, you shoul be able to see them too.

It says you have spacers installed too. If thats the case your car must be deflapped too.

[dubvag]

Yes, real pita to install, you shoul be able to see them too.

It says you have spacers installed too. If thats the case your car must be deflapped too.

I did know it has the spacers as well as a JHM tune. I thought the deflapping was optional with spacers and the tune.

If it is deflapped, what are the linkage arms doing?

Sent from my PH-1 using Audizine mobile app

[AA 954]

I did know it has the spacers as well as a JHM tune. I thought the deflapping was optional with spacers and the tune.

If it is deflapped, what are the linkage arms doing?

Sent from my PH-1 using Audizine mobile app

Good question, given that you were getting an EPC and apparently changing that front vacuum sensor has fixed it, I would say that your tune does not include the coding out of the arms which is something I believe their tune does, I’d reach out to JHM just to confirm

On the invoice it doesn’t say anything about eliminating the flaps however you have to remove them to install the linkage arms. Only way to be ceratin is to get a boroscope camera into the mani where the TB is connected although that would be kind of tricky to get it to curve enough up through the lower section where the trumpets are and then down again to see if the flaps are on I personally thought you had to eliminate both the port separators and flaps if you run their spacers, I also have seen folks post that they only remove the port separators...

[dubvag]

Good question, given that you were getting an EPC and apparently changing that front vacuum sensor has fixed it, I would say that your tune does not include the coding out of the arms which is something I believe their tune does, I’d reach out to JHM just to confirm

On the invoice it doesn’t say anything about eliminating the flaps however you have to remove them to install the linkage arms. Only way to be ceratin is to get a boroscope camera into the mani where the TB is connected although that would be kind of tricky to get it to curve enough up through the lower section where the trumpets are and then down again to see if the flaps are on I personally thought you had to eliminate both the port separators and flaps if you run their spacers, I also have seen folks post that they only remove the port separators...

https://jhmotorsports.com/jhm-tuning...l-fsi-32v.html

This makes it sound optional. I would assume I still have the flaps if I'm getting the P2020 code, otherwise their tune would eliminate those codes.

Sent from my PH-1 using Audizine mobile app

[dubvag]

Well EPC has come on a couple times and CEL popped back up last night.

Also, not sure if this means anything but I've noticed most times the EPC light comes on is while I'm in stop and go traffic like at a stop light or 4 way intersection where I keep just creeping forward with small throttle inputs. Not sure if that means anything as to what the issue is or not.

Sent from my PH-1 using Audizine mobile app

[dubvag]

Tried the CRC Intake Cleaner yesterday morning and the EPC light reared its ugly head again today. Looks like I'll be needing to pull the IM off to replace the potentiometers since my code is for the one in the back. Might as well do the carbon cleaning, PCV valve, and injectors as well right? Anything else I should be doing while in there? Does it make sense to do HPFP's and plugs and coil packs at the same time, or is that just as easy with the IM on.

[AA 954]

Tried the CRC Intake Cleaner yesterday morning and the EPC light reared its ugly head again today. Looks like I'll be needing to pull the IM off to replace the potentiometers since my code is for the one in the back. Might as well do the carbon cleaning, PCV valve, and injectors as well right? Anything else I should be doing while in there? Does it make sense to do HPFP's and plugs and coil packs at the same time, or is that just as easy with the IM on.

Well at least you tried lol, yes do potentiometers and injectors, you’ll need new clips too so source those from ebay. Have them check under IM to see if there are any oil leaks, if thats the case theres a valley pan gasket and another one at the bottom of the oil filter housing...

Sparks and plugs is just as easy as with IM off or on same as HPFP (makes no difference), are getting misfire codes too?


Sent from my iPhone using Tapatalk Pro

[dubvag]

Good to know. No misfire codes or anything, but I'm thinking it may be wise to do. I didn't get a ton of records with the car so I'm not sure when/if those items were ever last replaced.

Well at least you tried lol, yes do potentiometers and injectors, you’ll need new clips too so source those from ebay. Have them check under IM to see if there are any oil leaks, if thats the case theres a valley pan gasket and another one at the bottom of the oil filter housing...

Sparks and plugs is just as easy as with IM off or on same as HPFP (makes no difference), are getting misfire codes too?


Sent from my iPhone using Tapatalk Pro

Sent from my PH-1 using Audizine mobile app

[AA 954]

Good to know. No misfire codes or anything, but I'm thinking it may be wise to do. I didn't get a ton of records with the car so I'm not sure when/if those items were ever last replaced.

Sent from my PH-1 using Audizine mobile app

You mentioned further above the vehicle had 90+K miles, I’d definately change the injectors if you are pulling the mani off and like you wrote you don’t have a ton of records. A few of us did the fuel pressure regulators too (theres one on each fuel rail)

HPFP seems to be an item some change around that mileage however if you have no issues at this point or misfire codes I’d just stock up and change it when you need to, probably have your mechanic run a log for both the lpfp and hpfp, unfortunately if I recall the hpfp’s only have one sensor that reads the pressure for one of the fuel rails so you don’t really get to confirm if the other is working properly (I might be mistaken and someone else can clarify)

Buy your injectors on Rockauto or FCP, the hitachis ones that they list are OE but without the 100$ audi tax on each injector just because iof the audi stamp


Sent from my iPhone using Tapatalk Pro

[dubvag]

I'll finally be pulling the intake manifold off later this week to do a carbon clean, replace injectors and plugs, potentiometers, PCV valve, and fuel pressure regulators. I also purchased a new valley pan gasket and the double o-ring gasket for the oil filter housing in case they are needed. I can see a little bit of oil in the valley right now, but nothing ever leaks onto the floor.

I'll let you know how it goes!

[dubvag]

Well I pulled the manifold off over the past weekend and did a carbon cleaning as well as replacing all the parts I ordered. Still getting the EPC light though and it's actually coming on more consistently now as well as giving me the P2020 and P2015 codes. Def, another user on here PM'd me and said he's having a similar issue with his car. The guy he takes his RS to said the 034 arms require a set screw or two. So that's another thing for me to look into.

I did notice when the manifold was off that the flaps have a bit of play. I would assume they shouldn't have any play? Either way it's my daily so I had to put everything back together. Car still seems to run great and the carbon cleaning was a very satisfying job. I need to find someone around me with VCDS to see what's going on with the flaps.


Clean, clean, dirty, clean



All buttoned back up

[dubvag]

Well I'm not sure if anyone is still following this, but my CEL and EPC lights are still on.

I did order the VCDS tool and ran the test to see if my power flap in the air box along with the intake flaps were moving at all. They didn't appear to even budge during that test. I then used VCDS to monitor/log the intake flaps as I drove around for about 10 minutes. The flaps don't appear to be totally stuck because they moved a little, but mostly hovered around around 20%. They should be at 0% until 4k RPM where they should be 99.6%.

Here's a link to the instructions I followed: https://forum.rs246.com/viewtopic.php?t=77235
Here's a link to my intake flap log if anyone is interested in taking a look: https://drive.google.com/file/d/1S6c...ew?usp=sharing


I'm not really sure what this information should point me towards next. I did try testing for a vacuum leak with a smoke machine, but I was unable to locate a leak assuming I was getting past all the check valves and solenoids.

[1975audi]

Any updates on this.
I'm getting the p2020 and p2015 codes as well.
Pulling the I.m off and checking for bar vacuum lines and changing the front solenoid.
Hopefully that fixes it.I hope

Sent from my SM-G955W using Audizine Forum mobile app

[Airnautique54]

I struggled with EPC and CEL lights post carbon clean for about 20k miles. Replaced sensors, confirmed via Audi Dealership no vacuum leaks, replaced linkage arms, confirmed actuators were working... finally gave up and went with the JMH 91 octane tune (I still run 93 oct fuel). About 7k miles into the tune, couldn't be happier... finally no CEL or EPC lights and the car runs great! Hopefully you can figure i tout and leave all stock, this was my #1 option, but after $$$ and frustrations I'm glad I ended up settling on the route I did!

[1975audi]

Nervous about jhm tune.
My car has 222,000klm
Is the 91 tune less aggressive,

Sent from my SM-G955W using Audizine Forum mobile app