AIrey1507

2006 C2 (3.6) with 57k miles. Ran into my first "issue" with my 997 this past weekend. Car has been running great for the year & 12k miles I've owned it, just changed the oil again last week. Well I was overtaking at the top of a nice, clear long downhill stretch and got into the gas a bit. Shifting from 3rd to 4th (or maybe just near the top of 3rd, not sure), all of a sudden got the dreaded Check Engine - Visit Workshop with solid yellow engine light. Car was definitely misfiring but temps, oil pressure were all stable. Limped it a few miles to an auto parts store to get codes read and wait for a tow. Other than seeing multiple misfire codes across multiple cylinders (P030x), also getting P2231 (O2 Sensor Signal Circuit Shorted to Circuit Bank 1 Sensor 1), P0112 (Intake Air Temperature Sensor 1 Circuit Low Input) and P1090 (store scanner wouldn't give description, but appears to be MAF related). Believe the latter 2 codes, at least P1090 but not sure about P0112, are due to me unplugging the MAF sensor and restarting to see if that resolved. Car is safe at home while I wait for Foxwell scanner and new plugs/coils and AOS to arrive. Maintenance I was planning in the spring but might as well get to it now....Will likely bring to the local Porsche specialist as I don't have confidence in doing plugs/coils myself, and definitely not AOS.

Any way to tell how potentially major this can be? I have not visually inspected the coils but assume they are "due" even though they are not in the regular maintenance schedule. This was an hour into a spirited drive, starting with full tank, so I doubt bad gas. Obviously bad plugs/coils or a bad O2 sensor will lead to misfires, but wouldn't that be something that starts occurring with a minor misfire (maybe not even noticed at first) and building in frequency/intensity? In my case, it was an hour of "all systems good" to instant "oh crap." I know best thing to do is tow to the shop for diagnosis, which I will do once parts arrive, but what good is this forum if not to solicit comments to make me worry even more. So any and all input is appreciated - TIA!

Petza914

I think you're on the right track with plugs and coils. It didn't happen to be wet that day did it - coil issues occur more frequently when it's wet and the water gets into the cracks. Also, how old is your battery. If it's not charging well even if the alternator is working properly, you can have issues like this, however with an all of the sudden O2 sensor and MAF error and it happening at high rpm, it sounds more like an intake hose or AOS hose let go and created a major intake leak. I'd smoke test the intake and see if you have any leaks.

AIrey1507

Plugs and coils did the trick!

Petza914

Good deal !