Recently bought a 2004 Grand Prix GTP Comp G(stock as far as I know). When I first bought it abs/trac/stab lights and check engine was on. The car would also go into limp mode every 10 miles. The car would idle rough and stumble/backfire under heavy acceleration.
Replaced plugs, wires, coil packs, oil change, pedal assembly, and fuel filter.
Its now a month later and the car seems like its worse than when I bought it. I did replace the pedal assembly and it eliminated the car going into limp mode. The car idles fine when first started and then begins to idle rough. If you drive it 20 miles and attempt to let it idle at a stop light or in park its so bad it actually kills the car at times. If you can get it cruising it usually will run decently unless its going up an incline where the car will cut out for a moment and return to normal. Also, while the car is getting into the high rooms before shifting it stumbles and sounds likes it backfiring.
Took my kids out the other day, drove 22 miles and went to DQ, the car was idling so bad it died. Rough start up and it drove so bad I went to my husband's shop instead of driving all the way home. Put the scanner on it and he took it for a drive, of all times the gauges stopped working, everything on the dash stopped moving (lights still illuminate) and the car ran the BEST it ever has except for the hang shift. Next day, gauges are back on and the car runs like crap again.
Codes that are coming up are:
C0898
P1362
P1361
C0550
Prior codes that came up after gauges failed:
C0896
U1096
U1016
U1000
P1626
P1362
P1361
C0550
C0898
I've been told since the gauges went out and the car ran good and once they came back on it ran rough again that I should replace the cluster and it should solve the problem.
I'm at a loss here. Anyone have any insight?
Thanks!
