2002 Pontiac Grand Prix Hesitation

CHUMBLEY1

MEMBER
2002 PONTIAC GRAND PRIX
6 CYL
2WD
AUTOMATIC
99,000 MILES

I have a 2002 Grand Prix and when driving down a highway/interstate, the engine sometimes hesitates/runs rough, like its gasping for power and you can see the rpm gauge fluctuating as this is happening. I have already replaced the spark plugs, added fuel injector cleaner and replaced the fuel filter. I have thought of a few other things it could possibly be but want an expert answer, thank you.

3 Replies

MMPRINCE4000

MECHANIC
8,548 POSTS

If the ckeck engine light is on or not, have it scanned at any autoparts store for free, Look for hard or pending codes.

Check fuel pressure with a mechanical gauge.

Other possibilities are the ignition module, crank sensor, excessive EGR flow.

Is this the 3.8 or 3.1 V6?

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Thursday, November 27th, 2008 AT 7:35 AM

CHUMBLEY1

MEMBER
2 POSTS

It is a 3.1 liter. I wondered if it could have been the o2 sensor or the idle air control valve or EGR issues. Thank you for the information and suggestions.

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Thursday, November 27th, 2008 AT 9:12 AM

MMPRINCE4000

MECHANIC
8,548 POSTS

It is possible that the O2 sensors need to be changed, I like to change them every 100,000 miles.

Never hurts to clean the TB and IAC as well as the EGR pintle and base, since they can accumulate a lot of soot.

Still, you want to make sure you have adequate fuel pressure, and have the ign. Module tested. Also inspect the fuel pressure regulator vacuum line for signs of gasoline, if present, the FPR must be replaced.

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Thursday, November 27th, 2008 AT 12:57 PM