Pontiac Repair: 2003 Pontiac Grand Prix, mass airflow sensor, fuel delivery system

Question
QUESTION: I have a 2003 Grand Prix with a 3.8L that the engine light came on. We used a scanner and it showed the Mass Airflow sensor and the Mapping Sensor were bad. We have since replaced both. The light is no longer on. The car was driving bad before we got the code and it still is. When driving it, it will not pick up speed on the highway. It took me 2 miles to get to 50mph. It will rev up to 3000 rpms and not shift unless I left off the gas a little and then push again. It idles great but no pick up. The plugs and wires have been changed and also a fresh oil change. Any suggestions on what could be causing this?

ANSWER: Hi shiela:

Just a guess but maybe the exhaust is restricted. a plugged restricted exhaust will cause those codes to set due to the fact that the engine can't breath properly. take the front exhaut pipe off at the engine the front pipe has the catalitic converter in it. drive it with the pipe off and see if it has power then if so you found the issue. How about the fuel filter has that ever been replaced? a restricted fuel delivery system will cause a lack of power as well. good luck :-}


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QUESTION: If we would unhook the front exhaust pipe from the motor, would that burn up the valves?

Answer
no but you will need to hang the pipe from the body with metal wire or a bungee cord. you will not have to drive it far to know wether it has the power back or not. You should be able to tell right away if that was it and it has a restricted exhaust. That was a pretty common issue on the older ones say 2000 to 2001 years.