*DIY* - B5 1.8T Vacuum/Check Valve/SAI/PCV - Delete & Simplification

**ballinb5** · 05-20-2014 03:25 PM

Anyone have a part number for this piece? It is the rubber grommet on the false firewall and I think mine is leaking:

**Mad Cow** · 05-20-2014 03:37 PM

Should be 8D0611743B.

**MetalMan** · 05-21-2014 07:47 AM

Originally Posted by ballinb5

Anyone have a part number for this piece? It is the rubber grommet on the false firewall and I think mine is leaking:

May I ask why you think it is leaking?
This is a check valve, which will hold vacuum pressure for a while after the engine is off. If you move the check valve around it will suck air into it (which sounds like a leak) since it holds vacuum.

**GrapeBandit** · 06-15-2014 05:25 AM

I have eliminated all evap related crap under the hood, even that little square vacuum pump thingy under the coolant tank. what would be the effects if I eliminated the line going to the purge valve all the way back to the rear of the car? it starts at the purge valve, tucks down the passenger side wheel well, and runs to the rear on the bottom of the car next to the fuel lines? also, same question goes for the round plastic ball in the driver side fender (leak detection pump

), all related lines that run under the car to the charcoal canister, and even removed the charcoal canister?

**Sam091990** · 06-21-2014 07:24 PM

@walky - quick question, if I'm removing ALL the vacuum hoses should I plug both ports on the N112 or only the one that went to the combi valve and leave the other open? After looping the appropriate holes on the N249 should I also plug the 3rd port or leave it open? Looked through the thread and there isn't any mention of this if you're removing everything.

Edit: Also wanted to ask, if you remove all the vacuum lines but would like to keep the function of the N249, where could you get a reliable vacuum source from? Would routing it to the TIP be your best bet?

**garytightpants** · 07-08-2014 07:27 PM

some of the pics in the main write-up are not working.

**GrapeBandit** · 07-08-2014 08:07 PM

Originally Posted by garytightpants

some of the pics in the main write-up are not working.

bcuz popular guy

**walky_talky20** · 07-08-2014 08:36 PM

Bandwidth on pics will reset on the 11th or so, I think.

I'm working to move the pics to different accounts. But 'tis a lot of work to relink and all that jazz. And my 240k mile B5 is currently falling apart on me, so time is not easily had for such activities.

**99jimse** · 09-09-2014 04:45 PM

Any1 have the pics for this awesome write up? I saved them somewhere but can't find them. I knew when I was ready for this, the pics would be gone. If not, I so hope ur B5 behaves long enough for u to get some free time, lol. Good luck with it.

**Rodgman15** · 12-05-2014 05:46 PM

Just wanted to pop in and say:

1 - pictures are working

2 - thank you Walky.

**freekonwheelz1** · 02-21-2015 04:02 PM

Originally Posted by walky_talky20

There have been a lot of questions lately about doing Emissions system deletes on the B5 1.8T. User "absolutegtr" did a very nice writeup for the B6 1.8T guys here:
http://www.audizine.com/forum/showth...simplification

There is nothing quite like it for the B5’s. I hope this DIY writeup will stand in that gap.

Goals:
Simplify the under hood vacuum system.
Identify specifically what does, and what does not cause DTC codes (and subsequent Check Engine Light illumination).
Get rid of "all those check valves", after first understanding what they are for.

Note 1: There are differences in the vacuum and pcv systems between almost every year of the B5. I will do my best to identify the differences. That said, most of the deletes discussed here will apply to the 2000+ cars. The 97-99.5 AEB emission system is already pretty simple as it is.

Note 2: Since this is something I did a while back, it won't be a step by step type of thing. You can rip this crap out it whatever order you deem necessary and effective. Onward.

For each system, We will first take a look at the factory setup and determine what exactly we want to remove. We will be going through the systems in a piece-wise fashion for those that only want to delete certain parts. The following will be covered in order:

1. Secondary Air Injection system
2. N249 (Electronic Control of Diverter Valve)
3. Suction Jet Pump
4. Vacuum Reservoir (constant vacuum source)
5. Evaporative Emissions
6. PCV refresh

*If there are any errors in anything I've shared, extra information that should be added, or crap that I just plain got wrong - please do not hesitate to correct me on it. This is meant to be a resource for B5'ers, so your input is appreciated.

i know the simpler, the better and all, but what benefits does this bring? i mean i will end up performing this mod so dont take this as hate or anything. i am just curious if there are economic or power benefits to this mod as well as simplicity/clean engine bay.

**ray4624** · 02-21-2015 06:38 PM

The main reason I did it was so I didn't have to mess with any of the pcv stuff when I changed my tip for a larger turbo. It is also less stuff to replace when t eventually deteriorates.

Sent from my iPhone using Tapatalk

**walky_talky20** · 02-22-2015 03:33 PM

- Less points of failure.
- Less blank staring at the engine bay when you're trying to find a vacuum leak amongst 914 hoses, clamps, and check valves.
- Less to replace if you want to renew "everything".
- Less to put back on if you took it all apart.
- Less crap to rule out when it's not running properly (I mean...as if THAT ever happens).
- Etc, Etc.

**ipop07** · 02-23-2015 12:32 PM

Originally Posted by walky_talky20

- Less points of failure.
- Less blank staring at the engine bay when you're trying to find a vacuum leak amongst 914 hoses, clamps, and check valves.
- Less to replace if you want to renew "everything".
- Less to put back on if you took it all apart.
- Less crap to rule out when it's not running properly (I mean...as if THAT ever happens).
- Etc, Etc.

Been meaning to write and thank you for the work you put in getting this thread together. It literally saved my ass.
First of all, the people who worked on my car cut stuff out and never replaced stuff with resistors or anything, my car was running like shit and been getting codes. There was so much crap that i didnt even know where to start to troubleshoot.
This helped me cut out the unnecessary stuff and clean up the engine bay a little and then made it super easy figure out where the issues were and how to fix them...

Definitely worth the time, especially if you have (like me) big turbo and a bunch of work done to it, this stuff just gets in the way really..

**Murph_129** · 03-07-2015 08:04 AM

Originally Posted by Rodgman15

Just wanted to pop in and say:

1 - pictures are working

2 - thank you Walky.

Originally Posted by 99jimse

Any1 have the pics for this awesome write up? I saved them somewhere but can't find them. I knew when I was ready for this, the pics would be gone. If not, I so hope ur B5 behaves long enough for u to get some free time, lol. Good luck with it.

Here's a link to this guide in PDF format that I made.. Enjoy! :)

Also if the file source above doesn't work. You can get it here

**walky_talky20** · 03-07-2015 08:09 PM

Wow, Steve. That's really nice. I'm honored that you took the time to put that together. Thanks!

**RENOxDECEPTION** · 03-08-2015 10:15 AM

Originally Posted by walky_talky20

Wow, Steve. That's really nice. I'm honored that you took the time to put that together. Thanks!

Should edit that into the original post, walky, I like it also.

**MarcMiller** · 03-29-2015 07:53 PM

I wanna do this but being from PA i don't think i'll pass my readiness part of my inspection.

**jpulll** · 03-29-2015 10:15 PM

Originally Posted by MarcMiller

I wanna do this but being from PA i don't think i'll pass my readiness part of my inspection.

PM me I will explain my setup to you.

**chaoticdopey** · 11-05-2015 08:31 PM

so mr walkie talky is this the same procedure for the B6 that already has a write-up or is there different hoses? Im in california and i want to delete all of the evap/sai system and im not worried about smog as i had it smogged with the GIAC X Tune and a lean condition with no cat and no check engine light and the damn thing passed, suprised the hell out of me, being in california they dont put cars 2000+ on the rollers, they just hook up their obd2 scanner and it checks the sensors and to make sure there is no cel on, but ya takes 2 minutes to smog your car now as long as its 2000+...

**MetalMan** · 11-06-2015 07:56 AM

Originally Posted by chaoticdopey

so mr walkie talky is this the same procedure for the B6 that already has a write-up or is there different hoses? Im in california and i want to delete all of the evap/sai system and im not worried about smog as i had it smogged with the GIAC X Tune and a lean condition with no cat and no check engine light and the damn thing passed, suprised the hell out of me, being in california they dont put cars 2000+ on the rollers, they just hook up their obd2 scanner and it checks the sensors and to make sure there is no cel on, but ya takes 2 minutes to smog your car now as long as its 2000+...

B6 is different, and I think there's a similar DIY thread in the B6 section.
You won't be able to delete EVAP & SAI and still be able to pass the OBD2 readiness check... Removal of either system (let alone both) will trigger the CEL unless you have a tune that codes them out and allows readiness to set properly.
You definitely got lucky on the visual inspection portion, that they didn't fail you for having no cat.

**chaoticdopey** · 11-08-2015 04:49 AM

Originally Posted by MetalMan

B6 is different, and I think there's a similar DIY thread in the B6 section.
You won't be able to delete EVAP & SAI and still be able to pass the OBD2 readiness check... Removal of either system (let alone both) will trigger the CEL unless you have a tune that codes them out and allows readiness to set properly.
You definitely got lucky on the visual inspection portion, that they didn't fail you for having no cat.

can i delete every thing without any drivability issues? not worried about cel as i will get that taken care of latler, i just would like to know what on the b5 i cannot remove that you can on the b6 as i just got the xspower headers and the combi block off plate...

**maxiz1** · 01-17-2016 12:22 AM

Can I ask if you remove the SJP lines would you loose the the few stroke of vacuum assisted brakes when the car is turned off?

Anyway very nice write-up!

**RENOxDECEPTION** · 01-17-2016 03:09 AM

no, when I shut off my car I still have vacuum in the booster, and I hear it hiss when I disconnect it.

**maxiz1** · 01-17-2016 05:49 AM

Thanks. I wonder how that works since the brake booster no longer connects to the vacuum reservoir?

**MetalMan** · 01-18-2016 08:17 AM

The brake booster has its own check valve, so it will retain vacuum for days without the engine being on if the lines and check valve are in good shape.

Originally I removed the SJP in my car. SJP's whole purpose is to provide extra vacuum assistance to the brake booster when there is little/no vacuum in the intake manifold. Somewhat recently I reinstalled the SJP in my car and have noticed that braking force has increased in the scenario where I get on the brakes quickly after just getting off the gas. Previously the brakes would feel a little "flat" until vacuum was restored in the intake manifold.

**2stroke** · 01-28-2017 09:52 AM

Originally Posted by walky_talky20

Emissions system deletes on the VW/Audi 1.8 Turbo Engine.

Goals:
Simplify the under hood vacuum system.
Identify specifically what does, and what does not cause DTC codes (and subsequent Check Engine Light illumination).
Get rid of "all those check valves, after first understanding what they are for.

Note 1:
There are differences in the vacuum and PCV systems between almost every year of the B5.
I will do my best to identify the differences.
That said, most of the deletes discussed here will apply to the 2000+ cars.

Note 2:
Since this is something I did a while back, it won't be a step by step type of thing.
You can rip this crap out it whatever order you deem necessary and effective. Onward.

For each system, We will first take a look at the factory setup and determine what exactly we want to remove.
We will be going through the systems in a piece-wise fashion for those that only want to delete certain parts.
The following will be covered in order:

1. Secondary Air Injection system
2. Suction Jet Pump
3. Vacuum Reservoir (constant vacuum source)
4. Evaporative Emissions

I have a ( 2002 ) 1.8T ( 150 Hp )
Engine Code: AWT ( European engine code )

I would like to remove the SAI system because my SAI pump is seized.

I would need some help with how to do this without getting error codes

**RENOxDECEPTION** · 01-28-2017 09:59 AM

Tune + block off plate + plug TIP

**2stroke** · 01-28-2017 10:41 AM

Originally Posted by RENOxDECEPTION

Tune + block off plate + plug TIP

1. Can you elaborate on your answer in detail !
2. What is TIP ?

**xdewaynex** · 01-28-2017 11:03 AM

Originally Posted by 2stroke

1. Can you elaborate on your answer in detail !
2. What is TIP ?

Turbo inlet pipe, airfilter intake tube.

**gtsingh91** · 01-29-2017 07:10 PM

Walk, in your PCV refresh list, the first link is broken. What was that link directed to? I see the second link is the T and the third link is the PCV Check valve, but what's the first link?

**2stroke** · 01-30-2017 09:20 PM

Originally Posted by walky_talky20

PCV Refresh

Application Notes:
The parts I show here are applicable for 2001+ only.

As the vast majority of the interest here is the “PCV” system,
I thought I should address what I did to freshen mine up “while I was in there”.
When I pulled all this crap out, it was in quite bad shape:

All busted up and leaking and such.

Many people have decided to remove the PCV valve and the manifold connection to the PCV system and just vent it to atmosphere.
I feel that is certainly applicable to high horsepower/Big Turbo cars.
With a stock turbo, it is my opinion that simplifying and keeping the stock system working well is the best route.

Originally Posted by gtsingh91

Walk, in your PCV refresh list, the first link is broken.
What was that link directed to?
I see the second link is the T and the third link is the PCV Check valve, but what's the first link?

You will find all the necessary parts at 034motorsports.
I have bought a complete PCV silicone hose kit including billet PCV check valve from 034Motorsport.
( https://store.034motorsport.com/volk...cv-system.html )
Great Product

**WyGuy1.8T** · 05-19-2017 12:08 AM

Old thread, but I figured it would be the best place to post my question. I'll post a picture below of my current catch can setup. I have the 034 silicone pcv kit, capped off the lower nipple off of the VC, and ran the Y coupler as normal. Would be make sense if I just ran a line from the block straight to the catchcan, then from the catchcan to the TIP, and just put a breather filter on my VC? Note: this car is not my daily and soon will be a stroker with a gtx 3076r and I want to simplify as many things prior. I already deleted a/c, SAI, and the SJP. I decided to leave the n249 and Evap in.

Sent from my SM-G930V using Tapatalk

**Believer** · 05-19-2017 06:30 AM

Originally Posted by WyGuy1.8T

Old thread, but I figured it would be the best place to post my question. I'll post a picture below of my current catch can setup. I have the 034 silicone pcv kit, capped off the lower nipple off of the VC, and ran the Y coupler as normal. Would be make sense if I just ran a line from the block straight to the catchcan, then from the catchcan to the TIP, and just put a breather filter on my VC? Note: this car is not my daily and soon will be a stroker with a gtx 3076r and I want to simplify as many things prior. I already deleted a/c, SAI, and the SJP. I decided to leave the n249 and Evap in.

Sent from my SM-G930V using Tapatalk

I'm sure othesr will chime in. I believe if you are routing the crank case to your inlet pipe and leave the valve cover vented to atmosphere, this would potentially allow unmetered air to enter the inlet pipe. If you are running mafless this would not matter.

**RENOxDECEPTION** · 07-15-2017 04:25 PM

photobuckettttttttttttttttttttttttttttttttttt, you ruined the internet!

Anyone have the images to rehost on imgur? walky?

**walky_talky20** · 07-17-2017 06:52 AM

Yes. All the images are still there. I just need to rehost them all. Then relink them all. For all of my posts and DIY's. This will roughly take me the rest of my life. Thanks, Obama!

I've gotten several requests for this DIY in particular, so I will start with this one. Keep bugging me via PM about it and I will get around to performing the 1 million+ clicks it will require to do this. lol

**RENOxDECEPTION** · 07-17-2017 08:17 AM

Imgur is bae ;)

**walky_talky20** · 10-11-2017 09:48 AM

OK, so I didn't relink all the images, but I did use the "embed fix" plugin (while it's working) to create a PDF of the page with all the images. Here is that link:

>> PDF VERSION WITH PHOTOS - CLICK HERE <<

*Special thanks AZ users bajohnson1984, Chucky1 and the rest of you guys for bugging me until I did something.

**Chucky1** · 10-11-2017 01:10 PM

Originally Posted by walky_talky20

OK, so I didn't relink all the images, but I did use the "embed fix" plugin (while it's working) to create a PDF of the page with all the images. Here is that link:

>> PDF VERSION WITH PHOTOS - CLICK HERE <<

*Special thanks AZ users bajohnson1984, Chucky1 and the rest of you guys for bugging me until I did something.

Thank you kindly for doing this.