Hello,

I have rather common problem with "System Too Lean (Bank 1)". I have already read much of the stuff posted here and tried to do things with (MAF, O2, Vac Lines, Intake), didn't change the fuel filter though.

Yesterday I've tried seafoam thing as this worked well on my previous A4. I saw smoke coming from beh. the engine, probably from ex. manifold gaskets (had same thing with my A4), and I can hear noise from a passenger side every time a release gas which could be a leak. But this was there all time and never caused a problem before ... plus it doesn't appear to be significant (considering amount of smoke from seafoam and noise),

How big it needs to be to cause "Too Lean Condition" almost immediately after the codes are cleared? Errors returns after the first boost,

Coil packs and plugs were changed less then 4000 ago. Will try to replace them today also

It is 180 with chip, k4, cat back, intercooler upgrade e.t.c

Any help much appreciated

 

did you seafoam your oil or fuel? also are you sure its not just your diverter valve that is making the noise. mine is loud enough that i can hear it through the air filter box.

 

Cleaning the maf wasnt enough for me, but when I cleaned the IAT sensor, it cleared the cell after a battery disconnect reset of the ecu