Check Engine Light, Codes
First real warm weather here in Denver, and on comes my CEL. I recently completed 80K service (oil, timing belt/water pump, air filter(s), plugs).
Ran VAGCOM and here are the codes:
17519 - Oxygen (Lambda) Sensor Regulation: Bank 1
P1111 - 002 - System too Lean - MIL ON
17544 - Fuel Trim: Bank 1 (Add)
P1136 - 001 - System too Lean
Readiness: 0000 0000
Thanks in advance.
There's definitely a check valve or something that is eaten all up by corrosion behind/above the airbox:

Could that be the culprit?

Now I just need to figure out: Will any check valve do? Or do I need a specific part #? It doesn't look exactly like the really basic check valves sold all over the place for $13.
The parts were very expensive from Audi dealer. I ordered them online and even with overnight shipping I saved $30 off the dealer price. Part numbers were:
Crankcase Vent Valve
Mfg Part# 06A133528D
Vacuum Check Valve
Mfg Part# 058905291K
The Crankcase Vent Valve was kind of a pain, just because of the extremely tight quarters and single-use hose clamps Audi uses. But got it done and back running.





