Engine Mechanical problem
2000 Pontiac Grand Prix 6 cyl Front Wheel Drive Automatic 118000 miles
The car, after sitting for a few hours will start and idle for about ten minutes before it the rpms start going wild, it then drops to about 200 rpm and bucks in between 200 and 800 until the engine slowly stalls out. If I drive it it does the same thing if I step on the gas and try to get up and go. Its throwing out pcode P0449, which it has a new purge solenoid, new vent valve, new fuel pump and filter, and also has a new pcv valve. Im at a loss on what could cause this. Any help would be great. Btw the car is aGTP so it is supercharged with the 3.8 V6
If you are only getting the P0449 code, I would start by measuring fuel pressure with mechanical gauge.
Another possibility is a clogged CAT. If CAt is bolted on, remove bolts and inspect CAT, if you see any melted material, then CAT is bad.
November, 7, 2009 AT 10:21 PM
Totally weird, I found a forum with the same car and problem and said it was a mass air flow sensor. So I tried it and it worked! The P0449 code no longer and the car seems to be running stronger then ever!
November, 8, 2009 AT 8:01 AM
One would think that if the MAF was bad it would set a MAF code? : ).
November, 8, 2009 AT 9:09 AM
Lol thats y I wasted 150.00 bucks trying diff parts of the fuel EVAP system! Wish it would have set a code for it.