Missing power on my S5, around 50hp

[TonCoronel]

Hi all,

I have an issue with my S5 wich is driving me crazy. I bought my car second hand (imported from Germany to Netherlands) with around 50.000km on it. I always felt it wasnt as quick as I hoped it would be. I also own a B7 S4 tiptronic and that just feels faster then my manual S5.

I read a lot about carbon buildup on the FSI engines and therefore I decided to take of the intake manifold and cleanup the carbon(it was bad! alot of carbon buildup!) I also installed the 42draft catchcan after cleaning.

After the clean-up it did felt faster and I left it as it was, until I started to hear a rattle from underneath the car, I took it to a company that is very good with high performance cars and they did a dyno on my car, guess what 300,5 bhp max compared to some S4 V8 they tested that had 339hp.

After the dyno they heard the rattle to and we examined were it was coming from. It was coming from the exhaust! The mid section of the exhaust (the big muffler I believe it is called) was making this noise. They assumed that there was a metal piece inside this muffler that was broken and could be blocking the air stream and that could be the cause of the power loss.

Last week I had a Milltek Resonated exhaust including downpipes fitted, it didnt make any change expect for the rattle. I have Vag-Com / vcds and the company said that if I read the MAF sensor and multiply the value of the maf with 1.31 I get an estimated bhp. The S5 max MAF value is around 234 so that would be around 305hp.
I did the same with my S4 and guess what, the max MAF value is around 262 so that would be around 344 bhp. The S5 should already have about 10hp more so I am missing 50hp!.

I attached the logs of the S4 and S5, the S5 was done in 3rd gear and the S4 in 1 2 and 3 (because it shifts automaticly even in manual)

Does anyone have any clue what it could be or what to look for?
I can make other measurements to if it is needed.

[elf_cruiser]

I would focus back on the intake - maybe you missed some carbon deposits? Did you clean the intake as well as the valves? An easy thing to try would be to run some seafoam through the intake - might help and certainly won't hurt...

[Solution Six]

cross-response from AW below... :)

Keep in mind that the S5 is 354HP at the crank, not at the wheels as most dyno's actually measure. With an AWD car I would typically estimate about a 17% power loss at the wheels (some people estimate even more loss than that ** as high as 20%) by the time the power makes it through the driveline and to the ground.

This puts the S5 in the 290-300hp range at the wheels... which is where you appear to be coming in at.

According to many claims, the V6T powered S4's seem to be heavily underrated in their HP claims from the factory. I know APR has some dyno numbers posted of a stock S4 that they did before tuning that were coming in around 340hp at the wheels which would put the V6T up towards the 400hp mark of ACTUAL power output at the crank. That definitely pains me because I love my V8 for many reasons, but i would love the extra power as well.

[JimmyBones]

OP,

I would like to see three engine measuring value blocks (32, 140, and 211) and what the software coding level of the ECM is. I have had a few V8 S5s that have been down on power with multiple issues so those things can help me rule some things out and try to help you.

I have not see a rattle concern yet but that has been an issue with the throw out bearing and shift fork of a manual transmission making a noise when shifting.

[AofC_RR]

SolutionSix, he's got a B7 S4 that runs the 4.2 non-FSI. OP any mods on your S4?

[TonCoronel]

I would focus back on the intake - maybe you missed some carbon deposits? Did you clean the intake as well as the valves? An easy thing to try would be to run some seafoam through the intake - might help and certainly won't hurt...

I also cleaned the intake. Before taking of the intake we did the seafoam twice but didnt do much.

Keep in mind that the S5 is 354HP at the crank, not at the wheels as most dyno's actually measure.
This puts the S5 in the 290-300hp range at the wheels... which is where you appear to be coming in at.

I have the B7 S4 with the V8 engine and that shows much higher numers then the S5 I wasnt comparing it to a new V6t engine. Also the dyno measured to values at the crank and at the wheels, crank was 300,5 and wheels around 245.

OP any mods on your S4?

None, just plain stock.

I would like to see three engine measuring value blocks (32, 140, and 211) and what the software coding level of the ECM is. I have had a few V8 S5s that have been down on power with multiple issues so those things can help me rule some things out and try to help you.

Thanks for wanting to help me out, I will try to make these measurements tonight or tomorrow, does it have to be in a certain gear or certain rpm?

[Solution Six]

I have the B7 S4 with the V8 engine and that shows much higher numers then the S5 I wasnt comparing it to a new V6t engine. Also the dyno measured to values at the crank and at the wheels, crank was 300,5 and wheels around 245.

Ahhh... sorry, I assumed you were talking power at the wheels. Typically when I think dyno numbers, I assume at the wheels ** that's what happens when we assume I guess.

[Bigserve134]

cross-response from AW below... :)

Keep in mind that the S5 is 354HP at the crank, not at the wheels as most dyno's actually measure. With an AWD car I would typically estimate about a 17% power loss at the wheels (some people estimate even more loss than that ** as high as 20%) by the time the power makes it through the driveline and to the ground.

This puts the S5 in the 290-300hp range at the wheels... which is where you appear to be coming in at.

According to many claims, the V6T powered S4's seem to be heavily underrated in their HP claims from the factory. I know APR has some dyno numbers posted of a stock S4 that they did before tuning that were coming in around 340hp at the wheels which would put the V6T up towards the 400hp mark of ACTUAL power output at the crank. That definitely pains me because I love my V8 for many reasons, but i would love the extra power as well.

I test drove the V6T and I currently own a S5...there is no way it produces 400hp at the wheels. There is hardly a difference in speed between the two

[JimmyBones]

Thanks for wanting to help me out, I will try to make these measurements tonight or tomorrow, does it have to be in a certain gear or certain rpm?

No problem and I really like the V8 S5s.

I would be more worried about engine coolant temperature then a certain gear or rpm. This brings up a good idea to me so try this. These instructions are specific so try to follow them in order and trust me there is a method to my madness. I am also going to add another MVB (2) to the list and when I say cold engine temperature below I mean below 80 degrees Celsius.

1. Turn the ignition on and leave the engine off at a cold engine coolant temperature. Save the MVB 2, 140, and 211 readings.
2. Start the engine and save the MVB 2, 140, and 211 readings at idle with a cold engine coolant temperature.
3. Rev the engine to 2K rpms and save the MVB 2, 140, and 211 readings
4. Turn off the engine and turn the ignition back on then watch the same MVB readings for any changes over like two minutes.
5. Start the engine and rev it a little until the coolant temperature goes up to 80 degrees Celsius.
6. Check the MVB 32, 140, and 211 readings at idle and at 2K rpms.
7. Turn off the engine and turn the ignition back on then watch MVB 2, 140, and 211 for any changes over like two minutes.

If you can do those seven steps and save the readings it will just about cover all the bases.

[TonCoronel]

Ok, I will try this all out in a few hours and post all the results here.

[elf_cruiser]

What are we hoping to learn, JimmyBones? Trying to ID a bad sensor?

[TonCoronel]

Hi Jimmy,

here are all the reading:

1. Turn the ignition on and leave the engine off at a cold engine coolant temperature. Save the MVB 2, 140, and 211 readings.
Because these numbers are static because the engine isnt running I removed the extra lines:



2. Start the engine and save the MVB 2, 140, and 211 readings at idle with a cold engine coolant temperature.



3. Rev the engine to 2K rpms and save the MVB 2, 140, and 211 readings


4. Turn off the engine and turn the ignition back on then watch the same MVB readings for any changes over like two minutes.
Because a 2 minute logfile is pritty large I removed all lines but the ones every 10 seconds.



6. Check the MVB 32, 140, and 211 readings at idle and at 2K rpms.

At Idle:



At 2K rmps:



7. Turn off the engine and turn the ignition back on then watch MVB 2, 140, and 211 for any changes over like two minutes.
Because a 2 minute logfile is pritty large I removed all lines but the ones every 10 seconds.



Hope you can make some sense from all these figures!

[mateush]

I read a lot about carbon buildup on the FSI engines and therefore I decided to take of the intake manifold and cleanup the carbon(it was bad! alot of carbon buildup!) I also installed the 42draft catchcan after cleaning.

Did you do it yourself?
Is it possible to clean the valves with just the intake manifold removed?

[TonCoronel]

Yes, i did it myself, tooi me around 20 hours in total. Yes you can clean the valves with just the manifold removed

[mateush]

Yes, i did it myself, tooi me around 20 hours in total. Yes you can clean the valves with just the manifold removed

I don't want to change the topic of your thread, but any tips how to do it? Removing manifold would be easy, but I'm afraid that some dirt from the valves will fall into the combuston chamber.
Any special tools/chemistry needed?

Some DIY would help many of us :)

[JimmyBones]

What are we hoping to learn, JimmyBones? Trying to ID a bad sensor?

I am looking for multiple things because with a lack of power concern there is usually a problem with the air flow (intake or exhaust) or fuel pressure/delivery. Other things like coding issues are odd but they do happen and it has happened to me with an S5 which is why I asked for the software level but I am okay with not knowing it after seeing the values. Plus those four MVBs wrap up all the major issues that I have seen with the V8 S5s so far in a nice easy to diagnose package.

Hope you can make some sense from all these figures!

Oh I have made sense of them and here is my explanation:

As I stated before with a lack of power concern there is usually a problem with the air flow or a fuel issue. So the MVBs I had you look at showed those two areas. MVB 2 is a mixed bag that shows the rpms, injector on time, and the mass air flow specified reading. MVB 140 shows fuel pressure with the specified value and the actual value measured at the rail. MVB 211 shows the specified and actual air mass readings from the mass air flow sensor along with the correction factor that the ECM uses for those values and the absolute pressure. (did you notice both the MVB 2 and 211 show the mass air flow specified value?) Finally MVB 32 shows the fuel trim adaptions.

About the readings:
1. Starting with the first reading the most important thing here is fuel pressure MVB 140. The specified fuel pressure/called for fuel pressure by the Engine control module with the ignition on is 50 bar and usually I see 25 bar or so but the reading showed only 6.88 bar which is the most that the electric fuel pump in the tank can generate. So the fuel pressure in the rail went some where from when the car was turned off because the electronic fuel pump in the gas tank primes the system when the ignition is turned on and that almost 7 bar of pressure is nothing for an FSI engine.

2. Then at idle we can see that the actual rail fuel pressure does go back up to specified value so the mechanical fuel pumps and electrical fuel pump are working correctly. The injector timing does seem sort of low though because it should be between 1 millisecond to 5 milliseconds and it is reading 1.27 miliseconds which is on the low side of the scale. All the other readings seem okay and the air side of my theory looks good here.

3. At 2k rpms everything is reading fine except for the injector timing which drops below 1 millisecond at times.

4. This is the money shot reading here. If you look at the actual fuel pressure reading it just drops as time goes on so the fuel pressure is bleeding off some where when it should be holding steady.

6. The mass air flow readings are a little off at idle but not enough for me to worry about. Other wise the only other thing that stands out to me are the fuel trim adaptions that show bank 1 is running a little rich and bank 2 is running a little lean. For most other cars those adaption values are good but Audis are so close to dead perfect at 0% that this is something to notice.

7. This is more of a repeat of step 4 because it shows that the fuel pressure is bleeding off when it should be holding steady or raising for that matter since the engine has been heated up and that heat above the engine should soak into the intake manifold and fuel rail causing the fuel pressure to go up.

So in conclusion: I see that your car is not holding rail fuel pressure and it is bleeding off some where. This leads to four places that the rail fuel pressure could be bleeding off to. Those places are the top fuel injectors seals to the fuel rail, the metal high pressure fuel lines, (both of the those two problems would cause noticeable fuel to be dumped on the ground though and be very obvious), then the fuel metering valves in the mechanical high pressure fuel pumps could be leaking down (but there is no good way to see if those valves are leaking down so lets go with option D), or the fuel injectors are leaking into the combustion chambers though either the teflon combustion chamber seals or the fuel injector openings. Now with the injector timing readings that are really low the injectors are probably adding too much fuel because they are leaking into the combustion chamber so that is why they are not opening for very long. Then to try to figure out which bank of injectors is leaking more we can see that bank one is running rich from the fuel trim adaption values so I would assume the bank one injectors are the ones leaking down into the combustion chamber worst.

If you want visual conformation of the injectors leaking into the combustion chamber pull the spark plugs and turn the ignition on for a few seconds and then off. Next look down the spark plug holes for any thing that looks wet like fuel in the combustion chambers.

Now if I had to shotgun my diagnosis from here I would replace all eight fuel injectors by the dealer if you can get it covered under warranty otherwise I can help with that repair too.

I hope this massively long post helps.
Jimmy

[TonCoronel]

Sorry double post

[TonCoronel]

Hi Jimmy,

Thanks for the thouroug explination. I am glad that you found an issue with my car. Most people call me crazy when I say there must be something wrong with my car. I asked several dealers to look at this issue but none found anything, they all say there are no errors logged and it drives fine, and o yes please pay 200euros for diagnostics.

I assume that when the fuel lines would be bleeding that I would also smell the fuel?
There is no way I can find out if the high fuel pressure pumps are shot?

Unfortunatly my car is over 2 years old so my dealer wont do it under warranty. I have etka and elsawin so together with my friend who is a mechanic I should be able to do it, but your help would be more then welcome!
I know there are companys that can clean/fix injectors but is it better to replace them?

For other S5 owners that want to clean the carbon deposits, I am afraid i cannot do a DIY as my english is not that good especially with all the technical words. I managed to do it with elsawin wich describes in detail how to remove the intake manifold.

[TonCoronel]

Well I removed the injectors yesterday, some were pritty stuck. They all looked very dirty with carbon buildup on them.
I got them cleaned and tested today, none of them were broken but also none of them had a good spray pattern. They didnt test if they were leaking but with this spray pattern they thought it was very much possible. Also bought the injector repair kit (just some rings)for every injector at the Audi dealer. Will start putting the car back together tomorrow hopefully.

[elf_cruiser]

Good luck! Sucks that this carbon buildup problem is affecting so many parts of the motor...

[mage0608]

Hi TonCoronel, do you know where to download elsawin? Thanks

[rs4-380]

first thing that struck me was that the rail was not holding residual pressure but honestly I have no idea if an FSI engine is supposed to hold full pressure in the rail or not!

I could see it having some sort of pressure bleed down system for safeties-sake but jimmy bones has it more then covered and definitely deserves a drink on this one.

[JimmyBones]

Hi Jimmy,

Thanks for the thouroug explination. I am glad that you found an issue with my car. Most people call me crazy when I say there must be something wrong with my car. I asked several dealers to look at this issue but none found anything, they all say there are no errors logged and it drives fine, and o yes please pay 200euros for diagnostics.

I assume that when the fuel lines would be bleeding that I would also smell the fuel?
There is no way I can find out if the high fuel pressure pumps are shot?

Unfortunatly my car is over 2 years old so my dealer wont do it under warranty. I have etka and elsawin so together with my friend who is a mechanic I should be able to do it, but your help would be more then welcome!
I know there are companys that can clean/fix injectors but is it better to replace them?

For other S5 owners that want to clean the carbon deposits, I am afraid i cannot do a DIY as my english is not that good especially with all the technical words. I managed to do it with elsawin wich describes in detail how to remove the intake manifold.

I had a sneaking suspicion from the start that was the problem but I wanted to check the values to make sure. Trust me I didn't want to have to go through all the crap to find this stuff out.

The reason I was thinking the injectors were the issue was from the Q5 that I had leak on me. The client complained of a start and then die problem. She could usually then start back up fine or not or run rough sometimes and I could never duplicate the concern. So I had to call technical assistance and jump through all their hoops to figure this out. As seen here if the fuel injectors leak down the ECM will not set a fault. And to top of the nightmare Audi does not pay for diagnosis time for warranty issues so I lost three days worth of hours/money trying to fix this lady's car.

By the way the warranty over there sucks! Here it is 4 years/50K miles unless they get a CPO which works out to 6 years/100K miles at best.

Well I removed the injectors yesterday, some were pritty stuck. They all looked very dirty with carbon buildup on them.
I got them cleaned and tested today, none of them were broken but also none of them had a good spray pattern. They didnt test if they were leaking but with this spray pattern they thought it was very much possible. Also bought the injector repair kit (just some rings)for every injector at the Audi dealer. Will start putting the car back together tomorrow hopefully.

Yeah some times the injectors come out with the fuel rail but other times they stay down in the block and want to be a pain to get out. We have a special tool to pull the injectors out and it also is for putting those seals on because the teflon combustion chamber seals are very important to get on there correctly. It is important to take your time putting the injectors back in correctly and torque the lower manifold bolts because gas shooting out at 7 bar of pressure is a lot!

first thing that struck me was that the rail was not holding residual pressure but honestly I have no idea if an FSI engine is supposed to hold full pressure in the rail or not!

I could see it having some sort of pressure bleed down system for safeties-sake but jimmy bones has it more then covered and definitely deserves a drink on this one.

Oh yeah I could use a whole bar after the first issue I had with an S5 and it seriously made me consider quitting on the spot when I got my lack of a paycheck!

[TonCoronel]

Jup warrenty does suck over here! 2 years max

Put the car back together yesterday, car started after a few tries, ran terrible at first but after restarting the car 2 or 3 times it ran fine.

Measured the fuel pressure after shutting down the car when it was still cold. went down very slowly from 27bar back to 20 in about 5 minutes. Then started the car again and let it run for some time. After that I did the same test but this time the pressure went down much quicker from 27 to 10 bar in maybe 3 minutes. I checked all fuel lines and did not smell any fuel and didnt notice any leaking either.

I havent driven the car yet and dont have any new readings yet.

I assume that because the pressure will remain at around 6.7 bar that the problem can only persist IN or after the high pressure fuel pumps?
Are there any additional tests you would like to see to determine the cause of this issue? Maybe again the injector timings? Also is there a way to tell wich of the 2 pumps is maybe broken?

[mage0608]

Hi TonCoronel, can you post how to get those numbers through VAGCOM? so I can log mine and we can compare.....

[TonCoronel]

I drove about 100 miles today and after that I tested if my power was back, unfortunatly nothing seems to have changed.... below you will find a printout of a new reading with MSB 3, 140 and 103. I did the 103 because it should show the low presure fuel pump, and that seems to be working fine. What I did found strange is that the maximum fuel pressure is 105Bar(also the max specified according to vagcom) I thought it could/should go much higher to round 130Bar?

Mage0608 that would be very interesting to see.
- Open vagcom
- go to the "Select Controle Module
- go to the "01 Engine"
- go to the "Meas blocks - 08"
- Select the correct groups as JimmyBonus suggested so I think 2,140,211
- Select "Log" and specify a csv file location
- You can then click on start and it will start logging, I would sugggest do a run in third gear from 2000rpm to max.
- Then when finished do the same log but just after you turned the engine of, put the ignition back on else the vagcom cable will loose connection to the car. This should show you how fast even if the high fuel pressure will drop.

Logile with msb 3, 140 and 103

[mage0608]

thanks, will try after work today....

[TonCoronel]

Could you also do a log with msb 103 in it to see your maximum values?

[mage0608]

will do

[mage0608]

Hi TonCoronel, here is my log:

1. Cold car didn't touch for a week...



2. Start the engine...



3. 2000rpm



4. shut the engine...., here is the wired things happened... pressure kept raising to over 100.... tried several times same result....



5. 30mins later... pressure was dropping slowly.



6. engine start again.



7. max reading during full accelaration.. MAF 285

[EuroB6]

Im very afraid to get any new Audis since they are all FSI now. Carbon build up can screw things up, which I think you are suffering from.

[TonCoronel]

Thanks mage0608. This really shows some differences:
- maf values at high rpms just like between my S4 and S5
- fuel pressure when engine is switched off
- fuel pressure regulator and adaption shows totally different values under high rpms

Further more the 105bar max seems to be correct.

What it still could be is that the injectors are leaking, but can they be leaking so much that the pressure drops from at least 25 bars to 6 in just 2 minutes? Also if the fuel lines are leaking than I would assume the fuel was everywhere under the hood and on the floor.

Jimmybones is there anything more you can tell about these numbers? Should I order 2 new fuel pumps?

[JimmyBones]

Thanks mage0608. This really shows some differences:
- maf values at high rpms just like between my S4 and S5
- fuel pressure when engine is switched off
- fuel pressure regulator and adaption shows totally different values under high rpms

Further more the 105bar max seems to be correct.

What it still could be is that the injectors are leaking, but can they be leaking so much that the pressure drops from at least 25 bars to 6 in just 2 minutes? Also if the fuel lines are leaking than I would assume the fuel was everywhere under the hood and on the floor.

Jimmybones is there anything more you can tell about these numbers? Should I order 2 new fuel pumps?

Yeah depending on the model the max bar of fuel pressure changes. I have seen 120 bar before so I assume over a 100 is okay.

Try running the engine for a minute then pull all the spark plugs and look/smell for any traces of gas. If it is not noticeable then you have leaking metering valves in the high pressure pumps because fuel would be all over place if the lines were leaking. Before you order the high pressure pumps though you may want to remove the pumps and look at the camshaft followers for any signs of wear. These camshaft followers are supposed to have rollers unlike the 2.0Ts in the B7 A4s that are solid and wear through.

Sorry I haven't posted sooner but I have had A8 problems out the ass lately. It is not funny but I have taken out the full interior in sections of an A8 though four different repairs.

[TonCoronel]

Hi Jimmy,

We pulled the plugs and nothing was leaking so we assume the injectors are fine.
Therefore I ordered one of the two fuel pumps first (the cheapest) in the hope that was the one that was broken, no luck still pressure drop.
Ordered the second pump also and after replacing that fuel pressure is fine!!! it goes up to over 100 bar!! Wohoe!

So I was very happy we got it resolved, with this is mind I went out for a trip and did another log, unfortunatly the power is still the same:( and the MAF reading shows some strange numbers. I think that the MSB 211 show the actual MAF in the first column and the specified MAF in the second? look at the difference between the two from around 5200rpm, if we look at the same numbers from mage0608 both colums are almost identical with some small marges. His MAF values in both colums are never higer then 285 while mine goes up to 364 from 6200 rpm in the second column and doesnt go over 235 in the first one.

[TonCoronel]

I read a bit on the internet about the 364.08 MAF value and it seems it is a limition of VAG-COM that it cant read values higher then 364.08 because of the way the value is presented to vagcom. So that could mean that the ECU is requesting even more air then this 364.08. I assume the ECU is requesting so much air to compensate the amount of fuel being injected, that would mean that the ECU is still injecting far to much fuel???
I also had my ECU flashed by a tuner to compensate for rough behavior of the engine, could it be that they changed the specified maf values? Stil that would not explain the low real MAF readings though.

[TonCoronel]

Just to be sure you have all the numbers I did the same procedure again with all data logging, here you go


1. Turn the ignition on and leave the engine off at a cold engine coolant temperature. Save the MVB 2, 140, and 211 readings.
Because these numbers are static because the engine isnt running I removed the extra lines:



2. Start the engine and save the MVB 2, 140, and 211 readings at idle with a cold engine coolant temperature.



3. Rev the engine to 2K rpms and save the MVB 2, 140, and 211 readings


4. Turn off the engine and turn the ignition back on then watch the same MVB readings for any changes over like two minutes.
Because a 2 minute logfile is pritty large I removed all lines but the ones every 10 seconds.



6. Check the MVB 32, 140, and 211 readings at idle and at 2K rpms.

At Idle:



At 2K rmps:



7. Forgot this step but this only shows that the fuel rail pressure goes up


I also logged the lamdba sensors when the car was running idle, the numbers go up and down like crazy



One final thing I noticed was that when I just start the car and stand behind it there is more smoke coming from the left exhaust then the right one.... dont know if it has anything to do with my issues or if it is even an issue.... maybe a catalyst converter clogged?

[TonCoronel]

I remembered I placed a new MAF sensor about a year ago and thought I would give the old one a try but also no luck.

With my newer MAF the MAF values are between 228 - 238 at 5000+ rpm, with my old MAF they are between 216-226 but they both show that around 6000 rpm the MAF readings are sometimes near the 250-260 but then at around 6200 fall back to 215-220 just like it is being held back by something.

[TonCoronel]

Talking to myself mostly but maybe someone is reading a long I hope :D

I took another good look at the logs of mage0608 and most numbers are the same besides these:
- His low pressure is around 5.8-6.0 bar and mine around 4.8-5.1
- Fuel pressure regulator shows different values
- Quantity valve (N276) shows different values at high RPM
- Absolute pressure (I dont know what this number meens) this one drops as the RPM increase(to below 740mbar) on my car but on the other forum member it stays close to 1000mbar

I already replaced the fuel filter because I thought maybe the cause is on the low pressure side but that didnt had any effect. If the engine is not running the low pressure shows 6.7 bar but as soon as I start the car it drops to 5 bar.

So is it the low pressure fuel pump in the fuel tank?
What does the absolute pressure mean?

[TonCoronel]

YES YES YES YES its fixed! The upper valve in the manifold was indeed stuck, so I had to replace the manifold! Its about the only valve on the car that doesnt have a sensor to see if its working! So no stealer would have ever found this issue I am afraid.

Wow what a difference! the car pulls really hard, I have the car for about 16 months and only now have the full power available to me!

Below are two graphs, the first shows the MAF sensor value before and after the intake manifold replacement, this was done using vagcom logging.
Based on information on the internet people say that when you take the MAF sensor and multiply it by 1,31 you get a rough estimation of the HP the car produces. My car would now do almost 400HP so I guess the 1,31 is a bit to much for our cars. I did clean the carbon, injectors, K&N Air filter and replaced all 3 fuel pumps so I think the car is at its best at the moment.
So looking at the chart the difference in lower ranges is always around 30hp and at the redline it is amost 100 hp!!!! even if the 1,31 is to much then still at least a difference of 80hp! That all because of one little dent and a stuck plastic valve in my intake manifold!

[Bigserve134]

Congratulations! I am glad you resolved your dilemma. I think most would have traded theirs in long ago :)