I realize it’s been a while since I wrote anything new, that’s largely because work got insane the past few weeks. But, I’m clear of that now! I’ll pick up where I last left off, now that the story is complete. Feel free to refresh yourself if you need to read the previous post again.
The car was running completely different after replacing the MAF, but that pesky tone from the stereo was still there. So, I took it back to Audio Design and Mike was fairly certain the grounding cable plugged into the alarm sensor wasn’t causing the issue. He was right. Obviously, the grounding cable was moved elsewhere, and the alarm sensor was plugged into the correct spot (no more horn honking when I lock the doors!). But what was causing the tone turned out to be the stereo head unit itself. It’s been a while now, so I can’t recall exactly what the fix was, but they had to reverse the way some cable(s) run from the head unit to the amp. Anyway, it’s fixed now, and the stereo sounds amazing.
But, a funny thing happened on the way to LA…
I was fortunate enough to attend Luftgekhült 4 in Los Angeles early last month (May 7, to be exact). Luftgekhült is a gathering of air cooled Porsches, most of which or unique, important, or historically significant in some way. It was an amazing event, an incredible gathering of cars, and I’m very much looking forward to attending again next year. You owe it to yourself to go too!
LA is roughly a six hour drive from where I live, and this would be the first road trip of any type I would be taking in the 996. I wasn’t too nervous as I had replaced the MAF and the tone from the stereo was gone. Everything should be fine… but, it was my first trip in the car. So, I made sure to bring my Professional Porsche Scan Tool by Schwaben. As fate would have it, half way to LA the CEL illuminated on my dashboard. This made my wife very nervous.
At the next stop, I plugged in the scan tool and ran the diagnostics. It came up with these error codes:
P0507 – Idle control at stop
P1128 – Oxygen sensing adaptation, idle range, bank 1
P1130 – Oxygen sensing adaptation, idle range, bank 2
These errors aren’t serious and they could have been remaining errors that I had never cleared since replacing the MAF. So, I made note of these errors then cleared them. The car was fine for the rest of the trip, and the three days we were in LA. However, half way home on the return trip, the CEL illuminated again. This time, I got the same error codes mentioned above, plus two new one:
P0420 – Cat. conv. efficiency, bank 1
P0430 – Cat. conv. efficiency, bank 2
Admittedly, this was a bit unsettling. The car still ran fine, I wasn’t experiencing any problems. But, there’s clearly something else going on as the CEL has now illuminated twice. Again, I made note of the codes and cleared them from the car. The rest of the drive home was uneventful.
I figured something must be loose. The next morning I looked under the hood and couldn’t find anything wrong. I didn’t touch anything, I just looked. Nothing looked out of the ordinary. I called Bob at RMG and I brought the car in a few days later. This is where the story gets a bit embarrassing. But only a bit.
Turns out, the large hose that connects to the throttle was disconnected. Yeah, that could be totally my fault as I had to disconnect it to replace the MAF. I felt incredibly stupid, until it was discovered that the grommets that hold the air cleaner in place were almost non existent. Hooray! Not total user stupidity!
You see, there’s two grommets that hold the air cleaner in place. Those grommets had deteriorated and you could easily shake the entire housing, it bounced around like clothes in a tumble dryer. I realized that I likely didn’t tighten the hose clamp enough. Then, after about three hours of continuous driving, the air cleaner rattled so much that the hose to the throttle came off due to my apparent inability to tighten a screw correctly. We put in new grommets, tightened the hose clamps properly, and the car has been perfect ever since, and I’ve done nothing but enjoy the car.