02 Grand Prix Hesitation

I have a 02 Grand Prix GT with non-supercharged 3.8. Car has 96,000 on it and I notice that it hesitates going up a hill under a load. It "coughs" going up the hill and it is fine, usually when it trys to downshift. I tried putting fuel injector cleaner and replaced the fuel filter and it still does it. The dealer put it on the computer and there were no codes that came up regarding this problem. Transmission seems to be fine too.

Has anyone had this problem?? I'm trying to pinpoint the problem whether it is the transmission or maybe anything fuel related.

Thank You

Reply to
Matthew
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You might want to run a compression check and see if it's within spec. While it might not generate a code, an engine with wear on it might be getting weak enough to require the downshifting and the cough you mentioned. You might also put a pressure gauge on the fuel rail and check that your pump is up to snuff. Another thing to look into would be the miles of vacuum lines. An open vacuum source can cause all kind of gremlins to poke thier heads out.

Reply to
FBR

I have the same car, had a similar problem. turned out to be a clogged Catalytic converter, at 70k. it was still under the smog warrenty.

Reply to
trooper2000

Does your check engine light come on also. Mine came on last week and onstar diagnosed it and said it was a loose fuel cap. Was not sure if this was related to the catalytic converter.

Reply to
Matt

Hello Mathew, Mike de vito here, could be a weak fuel pump, have it checked. Mike De Vito

Reply to
Michael C De Vito

Trooper2000 is absolutely right. I am willing to bet that it is a clogged catalytic converter.

Reply to
Gif J. Peg

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