Hello,
I been fighting this problem for several months now and can't come up with a fix. The car is a 2001 A4 1.8T AWM motor. 90,000 ish miles on it. The car is chipped with a neuspeed 1.1 bar chip. Problems started early spring last year, before that everything was fine. I have been getting intermittent limp mode almost every time I go for a drive. Driving at highway speeds seems to make it go to limp more often then urban driving 45mph and under. CEL shows up randomly, often with limp but not always. Plugs have been replaced also new forge 007 was installed then as well, just did coil packs two days ago but didn’t fix the problem. Also getting misfires at start up for 1-2 seconds during the high idle, also did this with the old coil packs. When I installed the packs, I vag-comed it and it indicated many misfires at idle during 1st start when I installed them. I am thinking maybe the wiring harness is going bad? MAF has been cleaned with MAF cleaner a few weeks ago. Also I noticed on the boost gauge the needle jumps back and forth during boost sometimes, I don’t really remember it doing that a year or two ago, here are codes.
The 1st code is the one I have been getting for the last several months, the 2nd set is the misfires from the morning when I felt it studder/rough misfire for 1-2 seconds. Also the system too lean code is in there as well. Any Idea’s? Because limp mode is no fun!
Thanks, Jon




Tuesday, 23 September 2008, 21:12:28

VAG-COM Version: Release 409.1-US



Control Module Part Number: 4B0 906 018 CH

Component and/or Version: 1.8L R4/5VT G 0001

Software Coding: 16201

Work Shop Code: WSC 63351

1 Fault Found:

17536 - Fuel Trim: Bank 1 (Mult): System too Lean

P1128 - 35-00 - -







Wednesday, 24 September 2008, 21:17:22

VAG-COM Version: Release 409.1-US



Control Module Part Number: 4B0 906 018 CH

Component and/or Version: 1.8L R4/5VT G 0001

Software Coding: 16201

Work Shop Code: WSC 63351

4 Faults Found:

16684 - Random/Multiple Cylinder Misfire Detected

P0300 - 35-10 - - - Intermittent

16685 - Cylinder 1 Misfire Detected

P0301 - 35-10 - - - Intermittent

16686 - Cylinder 2 Misfire Detected

P0302 - 35-10 - - - Intermittent

17536 - Fuel Trim: Bank 1 (Mult): System too Lean

P1128 - 35-10 - - - Intermittent

 

A bad maf can cause random misfires and all the symptoms you describe. Since you already replaced your coil packs and plugs there is nothing left to suspect but the maf since you don't have an ICM. MAF cleaner is pretty much a gimick in my opinion. There is no magical spray that is going to repair a tosted sensor element. The only thing it would be useful for is maybe cleaning oil off the maf caused by an over oiled cone intake or something.

 

I was throwing most of the same codes and replaced coil packs and plugs along with the MAF and it did the trick. gl

 

Check your readings on block 032 with the vagcom. The 02 sensor is a wear item, as it wears the ecu has to keep adding more fuel even though the actual AFR hasn't changed. When this happens the ecu tries adding more and more fuel causing the car to run much richer then it should and this will cause misfires. The lean code is usually thrown becaues the fuel trim readings become to high, this is usually around 25%.

 

I have been having these same exact problems with my 01 as well and it looks like the same software version. system lean, then i cleared the codes and the engine stumbled each morning after startup. i switched the coild packs and it still stumbled but didnt throw a missfire so im hoping everything is finally worked out. I'll be keeping an eye on this post for updates.

 

i would agree with mike that it might be the 02 sensor. especially if you cleaned the maf and replaced the coil packs already.

 

Just make sure you don't have any broken vacuum lines or check valves before replacing the O2 sensor.
Im going with a vacuum leak over an O2 sensor on this one.

 

I would do a visual check of all hoses associated with the intake to make sure you dont have a leak anywhere caused by a crack or two. Good Luck.

 

what are you boosting to on your boost gauge? i didn't think a leak would cause a misfire, well unless its a big one

 

A broken vacuum check valve would.