Service Engine Soon Light - Idles rough

[BuickGN3838]

Along with my brake problem, while driving the car, my Service Engine Soon light kicks on and the car idles rough at a standstill, and smells (like the converter is messed up). It actually sounds like the car has a cam the way it idles... I shut the car off, start it up, it runs fine again. It may be okay for 10 seconds, it may be okay for an hour until it happens again. I've changed the O2 sensor and also the Wastegate Solenoid module. I know it could be a number of things, but just wondering if anyone has any ideas as well.

[87 GRANNY]

Sounds like an ignition problem relating to engine temp. like a ignition module or coil pack. See what code is being displayed and this could narrow down the problem a bit. Also make sure you have a good mass airflow sensor because these were terrible for causing this condition also-just give it a smack with your palm and see if you can duplicate the stumbling condition.

[BuickGN3838]

Thanks for the information. I'll need to hook it back up to the computer and double check the code. If I remember right, I thought it came up as a wastegate solenoid module. I replaced it, but it didn't fix the problem. I have tried the mass air flow tapping. A buddy of mine has a GNX and he told me that would work as well, but we tapped and it appears that is not the problem. I'll have to check the code again. Thanks for the info...

[killahertz]

just got mine and does same thing but i have no light on, idols high too, but i am having a knocking in the valves like needs more fuel or you put crappy fuel in a high compression motor, only rattles when boost is 14 15 pounds thats as far as the guage goes

[BuickGN3838]

Mine is sorta like a bad O2 sensor. It smells like sulfur when it acts up, and feels like it has a large cam with the lope to it. You're problem sounds like something that happened to mine when I ran my chip. Even though I backed my boost down to 15-16 lbs, it still had a ping. Almost sounded like taking two spoons and tapping them real fast on the table. I had to run some 104 octane boost in my gas. Try some of that. If that doesn't fix it, then it's a different issue. Good luck !