I have a 1998 Grand Prix GT. Just replaced the lower and upper intake manifold gaskets to fix the problem, but it did not work. during disassembly, I saw the saw the classic puddle of oil in the corners of the lim. I got everything cleaned and reinstalled, replaced plugs and wires (it was time for a tune up anyway). When the engine is cold it runs like a sewing machine. After about 10 minutes the car starts to have multiple misfires and within a minute after that it dies and will not run correctly until it is once again stone cold. Has anyone else had this issue? Any help would be greatly appreciated.

Be sure to check that the plug wires are installed to there correct locations. Also double check your work.

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1999 GT|SLP CAI|Borla Catback| Shift kit|18" Koblenz|GMPP Lowering|GMPP handling|Blk Headlights|ER Rcokers|HV3|HV TB http://www.fquick.com/The_Guz

I know i did all the work correctly, and the plug wires are installed correctly. the condition did not change after I was done with the LIM/UIM and tuneup. there is something else wrong.

i would suggest cleaning your throttle body it it were like super gunked it could cause this and it helps to clean it ever so often any how, as for the misfire i'm not sure, do you have any codes coming up at all?

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BRAP BRAP BRAP nuff said

You may also want to clean up the IAC valve while you are cleaning the throttle body. Are you getting any engine code lights?

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1999 GT|SLP CAI|Borla Catback| Shift kit|18" Koblenz|GMPP Lowering|GMPP handling|Blk Headlights|ER Rcokers|HV3|HV TB http://www.fquick.com/The_Guz