Well while driving the car back to midas to look at the ses light it goes off... So the light went off and I decided not to go to midas. What would cause the light to just go off now. Obviously it is fixed now or the computer thinks it is ok now. I really don't think it is my cat for the fact no rattling or noise from it. If it is the o2 sensor maybe it is intermittent. Well just wanted to see what your thoughts are on why the light would just go off on it's own.

DTC's often reset after XX amount of times where a set parameter was not seen. Though you may think the problem is fixed once a DTC's presents itself, its just a matter of time before it comes back.

Your absolutely right it just came back on...so to midas I go.

GM seems to use three different things.
1. Resets when the car is restarted and problem doesn't appear with initial tests
2. 3 consecutive drive cycles
3. 50 Drive cycles.

You probably hit the 3 test cycles and it went off. Yet the problem still exists.

Ok sorry about the long time no post...but been having alot of issues with my bonne...it is basically falling apart at 160K now. I ordered a new cat for it and midas will put it on for 75-100 depending on what needs to be welded, because now at low idle on the highway my car's engine is shutting off, I assume because the cat or exhaust is getting to hot or clogging. So I put it in park and restart and it comes right back on. But I know it is because of the exhaust and/or cat issue. I bought some seafoam to put in, but need some advise where is the best place to put it in the gas tank or the oil tank? It states on the bottle it can do different things depending on where you put it...I think to get the most benefit from it I would need to put in the oil crank. Please advise on where it should go.

Thanks Guys!

Suck 1/3 can in to a vacuum line then shut off the engine for about 20 mins, and the other 2/3 in the fuel tank. Change the oil shortly after doing this.

Can you advise me on how to go about putting it through the vacuum lines? Is it hard or easy? Any details would be helpful..Thanks Dan

That should be covered in tech info.

I've searched for it to no avail...can someone please post a link to where the PCV valve is on a 2001 bonneville SSEI..

Thanks,

Top of the supercharger, rear near the throttle body. It's a black oval cover that says PCV on it.