posted 08-16-2005 10:33 PM                  

Bottom line when cold or warming up I can accelerate aggresively and have not negative response. But once The engine is warmed up real nice, if I try to get in slightly agressive I get a sputter (somewhat like a backfire) and the check engine light comes one. I have tried using some gas/fueline additives but still have the same warm engine response.
Any thoughts to what I need to have checked or can do myself?

Thanks for your help
Dave (Head Hunter)

posted 08-16-2005 11:46 PM                  

I had a similar condition back in the days. Review my site for details of that event.
http://www.prowlerexcitement.com/DynoPhenomena/ulthm.htm

They checked out the check engine light and they came up with a "Mis Fire" and "Vacuum Leak" error.

The dealer wrote on my service slip.

RAN COMPUTER SCAN AND VERIFIED ENGINE MISFIRE AT #6 CYLINDER- TRACED SYSTEM AND FOUND COIL #6 DRIVER WIRES NOT SEATED INTO PCM BOARD. REPAIRED CONNECTION AND REPLACED FOULED OUT #6 SPARK PLUG. RECHECKED AND SYSTEM OPERATION NORMAL AFTER REPAIR.

It is possible you might have a COIL going bad or something as simple as the wires losing connection at the COILs right above your spark plugs. Double check your spark plug coil overs are fully seated and the clip to the COILS are fully inserted and locked into the clips.

Have them do a OBDII scan see if they come up with anything.

Good luck.