so my car was in limp mode for a while with a p1128(lean code) and would sputter and whine real loud on cold start up for a while and i couldn't figure it out so i finally took it to the dealer. They recommended new coils and plugs because when they scanned it they came up with misfire codes. So i put that in and it solved nothin so i took it back to them today and all they did was clear the codes drove it and they said it would go into limp mode and they scanned it and came up with the same misfire codes (P0300, P0301-302-303-304) and said it most likely is the turbo or the cat. This made no sense to me cause if it was the turbo i would be blowing smoke and if it was the cat i would throw a P0420. When i was driving home it would hesitate real bad and misfire of coarse and barely hit 40. then the cel would come on and it would run like nothing was wrong it would hit full boost and all then 10 min later it would hit 3-4 again like normal limp mode. What is the deal with my car?????????

2000 A4 1.8T

 

Have the codes read. P1128 is usually caused by a vacuum leak.
Misfires are caused by ignition coils and spark plugs.

 

i agree with a leak, your running too rich/lean and getting misfires. do a leak check. if it was misfiring on one cylendar repeatedly, try switching the coil pack on that one with the pack on another cylendar and see if it moves to the new cylendar (if it does its the coilpack) or stays in the origional cyendar (if it does its the ignition control module, near your airbox)

if its multiple or random cylendars its possibly a leak or something else. a turbo doesnt cause misfires.

 

i did have it scanned afterwards and it only came up with the misfire codes and the lean code just dissapeared. and like i said i replaced the coils and plugs and its still running like crap and i knew there was no way it was the turbo and i cant see or hear any major leaks that would cause misfires like this.

 

I had the same problem with mine, and it turned out to be my third cylinder coil. But I was under the impression you swapped your coils and plugs correct? If so what year is your car? Does it have an ICM? What about your fuel pump? Fuel Filter? When you say it wines on start up is it coming from the rear passenger side?

 

icm i believe it located on the intake. try not to drive it to much if your dumping raw fuel into the cat it will ruin it .

 

i have a 2000 so yes i have an icm and the whine on start up is from the passenger front. the dealership said the most likely cause for my issues is a broken blade in my turbo, but that makes no sense.

 

2000 does not have an ICM................ A bad MAF can cause a lean condition/code and also cause misfires. Since coil packs never fail on 00's, and there is no ICM, and along with those codes, I'd say it's your MAF.

 

that was my thought but i just replaced my MAF in like may..... and my bad i thought my car had an icm. So is a bad turbo even close to a good diog. or is the tech who looked at it completely lost cus i cant afford a turbo right now

 

Secondary air injection might make a ticking sound
after startup.