hey guys just picked up an 04 gtp had many of the 98-2003's but cant seem to track down my misfiring issue on this 04.
things ive done.
1. changed to steel lim gaskets.
2. new plugs and wires.
3. checked vacuum lines.
4.cleaned tb.
5. new fuel filter.
6. new air filter.
7. drilled holes before cat to see if it was plugged no difference.
i have no cel, however a couple days ago i got limp mode with code p1516 but has not been back since. dont dare throw a 100 accel pedal at it til i could be certain thats whats causing it to spudder terrible under 3/4 to wot you can run slight boost pulls good. till you hit that 3/4 mark then just sputters out. car is completly stock even stock airbox. anyone have any more ideas? idles great. 91 oct only been in it.
