P1276 Engine Code

[gmorris552]

I'm a newbie to forums so please take mercy.

I have a 2000 Porsche C4. Long story but...recently put in a rebuilt motor (same size, etc) at same time changed out the CATs (and all 4 O2 sensors) since some oil had gotten through the old ones. Have had some CEL issues since. was getting the P1128/P1130's - so thought the new CATs and/or O2 sensors were bad. Talked with the CAT supplier and he agreed to upgrade to the 'latest greatest' that were guanteed not to give a CEL. Well...after about 80 miles I got a CEL so dutifully searched the forum and saw the comments about the MAF so I took that out and cleaned it (with MAF Cleaner). Now I make it about 150'ish miles and get a CEL P1276. Have done this twice. I clear the CEL and start tracking it over - only get the 1276 and not bank #1, so can I rule out the MAF? It would be wierd to be a bad O2 sensor since all of them are only about 5,000 miles old. Also - I'm using the simple CodeKey Engine code reader - when I clear the P1276 - am I setting all the diagnostics back to default? (i.e. can I be masking that I may be about to get another code?).

Ideas?

[Dharn55]

P1128 is Fuel Injector cylinder #4 and P1130 is Fuel Injector cylinder #5. Not sure why you thought Not sure why this made you think the cats were bad.

P1276 is the Oxygen sendor before that cat on bank 2 (4-6 side so it includes cylinders 4 & 5). Did you check the connections/plugs for this sensor, or the wires. I damaged the wires on one of my sensors, happened to be the same one, and had to replace the sensor to get rid of hte code. Actually, I could clear the code with my Durametric, but it would come back in less than 100 miles.

I am betting it is the sensor.

[Loren]

P1276 Signal Delay Time for Oxygen Sensor Aging, Bank 2 – Above/Below Limit

Possible fault causes:

- Oxygen sensor ahead of TWC

- Leak ahead of TWC or in the area of the oxygen sensor after TWC

- Wiring (oxygen sensors exchanged)

I would highly recommend the Durametric software, a PST2, or PIWIS to read and reset fault codes on Porsches.

If this is the only code you get then the problem is only bank 2.

I would erase it and see if it comes back. If it does, you likely have a bad O2 sensor before the cat.

[gmorris552]

Thanks Lauren and dharn55. I will clear it and see what happens. I did look ahead in the Tech Manual about changing out the O2 sensor. It says to remove the whole CAT before removing the sensor. Is that true or can I just unplug and remove the sensor without taking the whole cat out?

Also - where do you recommend picking up the durametric SW and PST2?

Glenn