3 Codes: P1123, P1125, and P0455

[Jameslovesporsches]

Hey everyone,

Got those 3 codes on a 99 996 tiptronic. P1123, P1125, and P0455. Any suggestions on how to troubleshoot. Could all 3 be linked to a gas cap problem (esp P0455)? Also, does anyone know what needs to be fixed to pass inspection in Texas. Codes were read using an Actron basic code reader. Thanks again.

James

[Loren]

Yes, they could be. I would reset them and drive the car for a few days and see if they come back.

[Jameslovesporsches]

So, got rid of the P0455 code with a new gas cap!

However, still getting P1123 and P1125 codes. I found an earlier post from Loren, but don't really understand how to look into the suggestions:

The O2 sensors are just that - sensors. They are likely not the problem but the problem reporting mechanism.

P1123 Oxygen Sensing Adaptation Area 1 (Cylinders 1 - 3) - Lean Threshold

P1125 Oxygen Sensing Adaptation Area 1 (Cylinders 4 - 6) - Lean Threshold

This would mean that the fuel/air mixture is so rich that sensing is up to it's lean threshold and can not lean the mixture enough.

My list of probable causes are: fuel pressure too high; fuels injector(s) leaking; EVAP canister purge valve open.

Could be the charcoal canister (which should be covered under emissions warranty) or fuel pressure too high because of dirt stuck in one of the valves or a bad fuel pressure regulator vacuum connection. In the end all of these may be covered by your emissions warranty (unless it was caused by a dirty fuel filter/fuel).

Initially, I was thinking a MAF sensor cleaning was in order, but that's just me guessing. Need some direction... please help. EVAP canister purge valve... where around the rear of the car do I find it? Thanks for the assistance.

James