Car threw a O2 Bank 1 code while at the track, it was preceded for a few laps by the car not getting more than .4 bar of boost. Tech at the track cleared with the factory Porsche computer and both CEL and boost issue corrected. The code and the lack of boost issue never surfaced again for remainder of the event. I have never had this issue at the track or on the street before.

(2001 - 50k miles - original O2 sensors)

Anomaly?

Sensors on way out?

Too low an octane perhaps?

Any and all thoughts appreciated.

H_D

 

Are you running aftermarket cats? Had a similar issue happen to me at the track. After chasing codes and diagnosing several suspected culprits the issue it turned out to be a melted cat. Hope that helps.

 

Which O2 sensor was it - wideband or after the cat? I get the latter from time to time. I think that if it logs enough of them, it throws a CEL and goes into limp mode, which limits you to 0.4 bar. If it's the wideband, you probably should replace them. The other one just reports on how effective your cat is.

If there is no tech to clear the code, you can sometimes get it to clear by disconnecting the negative battery terminal. You might want to thnk about getting a Durametric. You can read and clear the codes yourself, as well as log data.

Jon

 

I am running a Cargraphic exhaust with 400 cell cats.

I do not know which sensor it was... I will reach out to the shop and see if he recalls.

I had sensors sent to the track with the thought of replacing them, but when the code never came back I started to wonder whether I should send back $580 worth of sensors as it might have been just "one of those things".

 

Oof! Was that for all 4, or just two? The widebands are used to measure AFR, and are part of the control system for fuel/air/boost. The post-cats are used only for info about whether your cats are working. I'd replace the widebands if they are acting flaky.

The Durametric can be useful for this as well. Monitoring your AFR's on a boost run can help you see how well your ECU is able to control.

Jon

 

50k, I'd replace the pre-cat 02 sensors as part of maintenance anyway.

Many times I see cat and 02 sensor codes that are usually NOT the sensors, but rather AF ratios that are off for other reasons...which then overloads the CAT with hydrocarbons resulting in a cat code

 

Are you running a 5 bar?

Replace your pre cat O2's and MAF.

 

Okay - Here are the codes I got on my stupid little Actron scanner...

P0172 and P0175.

As suggested above -- replace MAF and sensors and be done?