Pontiac Grand Prix Has No Power When Accelerating

Question:
I have a 2002 Pontiac Grand Prix. It does not have any get up and go. When I floor it, it bogs right down. I changed the fuel filter but it made it worse. I had it put on a scope at two different places and nothing came up because the check engine light is NOT on. Could it just need a tune up?

Answer:
Hello. I think I can be of some help. A couple common things.
1- The fuel pressure should be checked to see if that is the cause of your problems.
2- Mass Airflow Sensors can also cause this problem but would have a code stored.
3-The most probable cause by reading your condition is that the catalytic converter is plugged. This is a very common problem. That also should have a check engine light with a code p0420, but not always.

The good news is that GM has a special policy adjustment for a failed catalytic converter. It is under warranty for 10 years or 120k miles. The special policy adjustment has a GM policy #05551. FYI, a catalytic converter replacement job at the dealer would normally cost $400-$700

Question:
It runs fine until i press gas then the car feel like can not go faster like does not open gas at all if i press gas gently gradually it go more until a limit. Also if i am driving at 30 mph w/ light or no acceleration it start a failure in the engine, is possible vacuum hoses, or gas regulator? No check engine light appear on dash is this because a possible broken light? 1999 Pontiac Grand Prix gtp 3.8 SC.

Answer:
Trying to understand what you are describing, this may be a low fuel pressure problem caused by a plugged fuel filter or failing pump. This could also be a plugged catalytic converter. That gives the same feeling of a fuel pressure problem where you hit the gas and it will not accelerate. If by a "failure in the engine" you mean it is running bad, then the catalytic converter problem or bad spark plug wires causing an engine misfire could be your problem.

Question:
My 2003 Pontiac Grand Prix 3800 V6 will turn over, run for a couple of seconds and then shuts off. After about the 10th try it ran fine. My son says it has been difficult to start for a week or two.

Answer:
Hello and welcome,. This could be 1 of several problems. You could have a fuel pressure problem(bad fuel pump, plugged filter), Leaking fuel pressure regulator causing a rich condition- which would stumble and chug before it dies, or you could have a theft system problem.

If after it starts and stall, leave key on and see if the security/theft light stays on or flashes-that would indicate a theft problem. While it is acting up, will need to check these things.


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