Random Boost...

[DubAudi3]

I have an 01 A4 1.8T

revo software
ghl turboback
710n dv
evoms cold air

Randomly ive been hitting low boost numbers like 10psi spike and last week it was hitting 5 lbs spike... unplugged the battery for a few minutes and its back around 22lbs... no idea why this is happening... i have the "mooing" sound from my engine bay around 0 (no vac or boost) but other than that it runs perfect... and last i checked a few weeks ago i didnt have any boost leaks... any ideas? Kinda new to the 1.8T motor

[Seerlah]

Maybe you need to contact Revo Technik about this issue. Sounds more like a software issue with your ECU if you were to reset your ECU (via battery) and have it run normal with no boost issues spiking ~22psi.

[DubAudi3]

Yeah i will do that... car went into limp mode tonight 5lbs of boost, then CEL after 10 minutes... then randomly went back to full boost again..

[Seerlah]

Maybe you have some old fault codes on your ECU also and the software is sort of throwing your ECU into a loop. You can go to Autozone and use thier scanner to see if it pulls anything up. If it does, erase them and see if problem persists. (Vag Com would be better option though)

[DubAudi3]

P1128
Long Term Fuel Trim mult., bank 1
system too lean, sporadic..

This came up when i had a guy in our shop check the code, he told me to check for vac leaks, and if not that then it needs a MAF

[Nebone]

These MAFs should be recalled on 2001. They just keep going out.

Seerlah, sell your spare to him.

[DubAudi3]

hahah.. i work at a vw dealership my cost on one off a passat is about $127..

[Seerlah]

I'll sell you one for cheaper.

FWIW, I have a boost leak and my MAF is just fine. Boosting around 17psi and I should be ~22psi (waiting for air compressor delivery to find leak). If you had a leak, you just would not be boosting as much as you should. And seeing how you are sporatically getting 22psi, there might be a different issue involved. Maybe the MAF as you and Nebone22 suggests.

Try some CFC MAF sensor cleaner from Autozone before you dish out the $127 for a new MAF.

[NewFisher]

[QUOTE=nebone22;2789965]These MAFs should be recalled on 2001. They just keep going out.

AMEN!

[DubAudi3]

haha .. changed a vac. line and cleared the codes.. doing a boost leak test at some point this weekend before i get a new MAF