P2187 AUDI - System Too Lean At Idle Bank


Registered User
So Ive got a4 b8 CDNC engine . The check engine light came on and a scan shows this error msg.
Trouble codes:
P218700 - System too lean at idle, Bank 1
Engine was recently out of the car for piston/rings replacement.

I made a smoke tester and cant see any leaks, ( Introduced smoke via pcv to manifold connection pipe)
I cleaned the MAF sensor.
I checked the fuel cap
I checked the oil filler cap
I have obd eleven
it shows Short term adaptation of mixture formation bank 1:
-0.8 to 1.6 mainly 0.8 or 1.6

What should I check next?
Also is it safe to drive on a 6 hour trip at highway speeds?


Active Member
VCDS Map User
Have you checked your Exhaust manifold for leaks? You should be able to adapt your smoke tester to fit over the tail pipe which will pump the whole exhaust full of smoke.