I had a code read mas airflow sensor so I replaced
it but my car still acts like it looses fuel power and
rpms after 20mph then it drives great I can't seem
to figure this issue out any ideas ?
Try running some fuel injection cleaner threw a few tanks. Other wise you could check the spark plugs & fuel pressure, it should be around 30 lbs. I would need to know the engine size and if it is coil on plug set-up to give you more info.
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts