Bomar Shelby

Merrily rolling along the expressway today on the way home from my Kiwanis club luncheon meeting when the CEL popped on. When I arrived at my home I pulled out my Autel and ran the diagnostics.
First up was PO431 warm up catalyst efficiency threshold bank 2 hence the CEL. Then I had a bunch of other codes as well, 8053 electronic steering column continuously blocked.
, C174 convertible top control unit (comfort), POSIP C152 communication PSM control unit (drive), C150 communication DME control unit (drive), PTM 152 seat memory, C102 can single wire operation (comfort),
TPM C131 communication gateway control unit ccan (comfort). Anyone in the village have knowledge of these? I cancelled all the codes so we'll see what tomorrow brings
BTW, I see I also had that issue with the PO431 and CEL back in Sept of 2022 and just cleared the code then. 81,000 miles on the car ,2009 911 4S

Petza914

How old is your battery. Weird codes from multiple subsystems is often caused by low voltage. Could be the battery is going bad or maybe the alternator. I'd do some voltage testing.

Bruce In Philly

2009 C2S

Yea, stop into any service station and have them check the battery and charging system.

Peace
Bruce in Philly (now Atlanta)

Bomar Shelby

Yes, thanks, I sort of wondered about the battery and all those electrical codes. The battery is a 6 year old AGM that I I put on a charger/maintainer when I am not driving the car for 10-14 days. Seems to be starting fine but I will get it tested. I had forgotten that the CEL showed up in Sept 2022 until I searched the archives and found my own post. . It seems unlikely to me that the catalytic converter is the problem (which is apparently the most frequent cause for that code) . hoping more likely it is O2 sensor issue. I do have slight exhaust leak as we re-used the clamp/connector when doing the center muffler delete with SOUL crossover pipe and I can see evidence of that leak in soot around the clamp. But that is so far downstream I didn't think it would matter. Exhaust leak is another trigger for PO 431

Bomar Shelby

Went to Autozone for battery and charging system check. Repeated testing 3 times and every time both battery and charging system checked out 100% OK. All codes were cleared before I went there . Now will drive and see what if anything develops . I mentioned previously that there is some exhaust system leakage evidence as sooting around where we reused clamps when SOUL X pipe was added to replace center muffler delete. I know one of the reasons for PO431 is exhaust leak detected but I am not clear how much leakage triggers that.