Trojan Man

Last night I was driving around and noticed a strange hum that i've never heard before. Then about 30 minutes into my drive home, my check engine light (CEL) comes on.

I know that this is usually associated with the O2 sensors in the cats, but the noise I heard sounds like it's the engine itself. Could there be anything in the engine that throws the CEL, or is it always exhaust/cat related?

Could there be any danger at all if I continue driving the car with CEL?

TIA

Doug H

Mine came on my 996TT not too long ago. I called the dealer and dealer said unless it was flashing, probably safe to drive on for a little while. I went by just to have them get the fault cade and it was a fuel pressure code. He asked if I had left the gas cap off which I had not don't, but the light came on during some very spirited driving. He said might be the beginning of a problem, but no light since then.

So there are other things not exhaust related that can trigger the CEL. BTW, if anyone has any ideas about fuel pressure sensor that trigger light, I would appreciate any feedback on potential causes.

Jack

Ryan:

Several things in addition to the O2 sensor may trigger the CEL -- faulty MAF sensor, misfires etc. Have the dealer read the fault code -- should be covered by your warranty.

Doug H

Just call dealer and make appointment to read fault code and reset. I did and spent maybe a few minutes there.

Trojan Man

Thanks guys!

Here's my biggest concern: my car is chipped, and from past experience with other cars, when you bring the car in for mechanical (as opposed to trim) problems, they ask you if the car is chipped.

Do I lie and protect myself or come clean?

Tool Pants

Check with Loren on renntech. I think starting with MY02 they can do a system test with the PST2 and detect if there is a chip. You may get away with a MY01.

gaxor

I had similar problem. Noise coming from the front of the car, which turned out to be fuel pump. Power loss at higher RPM, and CEL light came on.

NC Bob

Talked to my dealer about chipping a TT. He said that the Upsolute may cause the CEL to illuminate and also eat the MAF. Trojan Man, when you have your CEL diagnosed, please post the results. I would like to know if the Upsolute caused the CEL to come on. I want to go the Upsolute route, but I've heard several of cases where the CEL light comes on and it is the result of the chip. If anyone else on this board has had problems with the Upsolute after several thousand miles, please let me know. TIA.

Trojan Man

NC Bob: I've had the Upsolute for roughly 7,000 miles and this is the first mechanical problem I've ever experienced with the Porsche.

I do know that the first couple revisions of the Upsolute software had bugs that tripped the CEL, but that was supposed to have been fixed as of 9 months ago, or so.

I took my car to Glenn's Porsche (independent) and he hooked it up to the PST2 and found 2 errors, both related to an air injection solenoid or something like that. According to him it's no big deal other than diminished performance. It is covered under warranty so I'm going to take it to the dealer.

NC Bob

Thanks, Ryan. I feel a little more comfortable. There is another TT owner located in Albemarle, North Carolina that also has/had the Upsolute. It would be good to hear from him as well. He's had it on for a while.

Trojan Man

So it was a blown air recirc. valve (diverter or blow-off valve). While it was covered under warranty, this is a FANTASTIC reason to switch to the billet DV.

Unrelated to the CEL/DV problem, there was also a bad pulley/belt that had to be replaced.

I'm concerned guys...I thought Porsche engines were bulletproof!

MBailey

Did the dealer replace the DVs with billet valves or OEM plastic ones?

Trojan Man

OEM plastic of course. Stupid dealer didn't tell me what the problem was until AFTER they fixed it, otherwise I would have insisted on the upgraded part.

dpj

Well that's typical Beverly Hills Dealer service for you.....they suck.

BCS996TT

Ryan,

Glad to hear everything worked out and covered under warranty.