I had my mother put in fuel injector cleaner for 2 tanks, but still no better. The idle is fine by the way, any more ideas? 
2002 Grand Prix problem, need help.
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2002 Grand Prix problem, need help. This is my mother's car. She had me change the fuel filter on it and it didnt solve the problem. The car has over 75k miles on it so it couldnt hurt to change it. The only thing that has been changed besides the oil was the air filter, nothing more. I just did a brake job on it last weekend. Anyhow, I looked at the air filter and it looked good like it may have been changed recently. Well here's the problem, well I go to accelerate, it response before it starts to pick up speed is slow, but then when it does pick up, it seems like low on power. I thought it wasnt shifting down to the right gear so I would manually shift it and its no better. So I floor the car and again, there's a delay before it starts picking up speed, but there's just no power to back it up. Now given its only a 3.1L v6, it still doesnt feel normal. It feels like it has a small 4 cylinder in the car. Anyhow, just wondering if anyone had any ideas on what it could be? Thanks.
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Well I no longer have the car and when I had it, I didn't think to check the idle.
Someone else suggested it could be the cat, any way to verify its clogged or not? If it is, any way to declog it or would it need a new one? How do they get clogged anyway?
Someone else suggested it could be the cat, any way to verify its clogged or not? If it is, any way to declog it or would it need a new one? How do they get clogged anyway?
If the car has ever run too rich for a long period of time, the cat starts to break down. You can hook up a vacuum gauge to check it. That car should probably read around 20 in vacuum. If it is real low, look at the cat. I'm not very familiar with the 3.1, does it have egr? If so, you may look at that. Do you have any way to look at the data stream from the computer? You could check egr temp and see if it's rising when the egr is off. It could be stuck open. Like 628soon said,"How's it's idle at a stand still???" The more info you can give us, the better we can help.
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Clogged cats? When I'm checking cars for clogged cats I use a vacuum gauge. Route a long enough vacuum hose to clip the gauge under the windshield wiper where you can see it while your'e driving. It's normal to have 17in vacuum @ idle(unless you have a fat cam 
)I usually get the car going on a straightaway and floor it and see if the vacuum drops to zero and stays there. If it does then unbolt the exhaust at the y-pipe and test drive. Should have a big diffrence in power. If your vacuum hovers around 2-4in under acceleration then your problem is elsewhere. Good luck...
)I usually get the car going on a straightaway and floor it and see if the vacuum drops to zero and stays there. If it does then unbolt the exhaust at the y-pipe and test drive. Should have a big diffrence in power. If your vacuum hovers around 2-4in under acceleration then your problem is elsewhere. Good luck... Thread Starter
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Well hopefully I'll get to try that out today. She is suppose to come later on this evening. So if I go to floor it and it drops to zero and stays, then its clogged? When I was driving it back to her, I did some more testing. At a 20 mph roll I punch it and it shifted down into 1st then slowly picked up speed, however, at 5000 rpms or so, it hovered the rpms and didnt pull past that so that it could shift into 2nd gear. I believe the shift points are around 6000 or so. Even if they were at 5500, it wouldnt pull it there, so the car didnt shift.
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From: Pearland/Houston, Tx
Everyone seems to say the Cats However my first thought is Plugs and Wires. My dad had a problem like this when he had his V6 Firebird. It ended up being that one of the wires had touched the exhaust manifold and had basicly burned a hole in the line. where there is no spark there is no power. Made the car accelerate horribly.
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Just wanted to let those who have kept up with this thread that my mother ended up finding paper work for her warranty and she thought she was covered to 75k and it was 77k and she took it in and sure enough, it was the catalytic converter! Its fixed and working fine now. Thanks everyone for your help.
