Cheesewiz

I just took my car in for smog inspection. At the end of testing he said check engine light came on, and he could not pass. It passed all other areas. Its an 08 gt2. Light has never been on before. Could he have done something to cause this with the sensor he puts up exhaust during testing?

P.J.S.

Car is stock?

Cheesewiz

High performance cats, and ecu upgrade.

P.J.S.

Hmmmm

I would get the light cleared, put a couple hundred miles on it and show up hot for a retest

You know the cats are in good shape I presume.

If they simply plug into your obd port, not sure how they could cause it

Here in lovely Seattle my ex 996-3 passed the joke emissions test with no cats - they simply plug in and verify there are no cel or emission codes...

Cheesewiz

Cats near new. California is a joke. Went to three smog inspection shops before i found someone who at least spoke broken Engrish.

stujelly

Mine went off after a few miles. I was because they ran the car on like a dyne machine

996FLT6

How many miles logged on high flow cats prior to smog? Are they the 100 or 200 cell type cats?If just put in- Steady state cruising can cause cel to trigger on hi flow cats. Mike

ChrisF

Mine threw a CEL on the smog rollers because it freaks out the PSM. Passes then had dealer clear. If you were on the rollers could just be that.

Cheesewiz

My son came over and read code for me. P0503. This reads the signal sent by the vehicle speed sensor to ECM is to high or intermittent. The check engine light came on at very end of test. I think what he did was turn off his equipment before shutting car off. This caused a intermittent signal, followed by engine light. Thanks everyone. Someone ask a roofing question so I can contribute

Daniel Ochoa

The same thing happened to me. I have never jad a check engine light come on. I went to get a smog check and now I have a light on. Code reads that its my O2 sensor or my catalytic converter. My opinion; the certified mechanic is a certified crook.