Hello everyone.

I have a 2002 LS with 125k on it. I recently have been having a big problem. When i drive the car will only rev up to around 2500rpms before it starts bogging down. I can get it to rev up higher after a little bit but it does not move faster.

At first i thought it was a transmmission problem. I took it to the local College and they ran a full test on the transmission and said that it was in great shape.

I was told next that it could be a restriction in the exhaust. I took my car to an exhaust shop and they said there was a small hole in the restricter pipe but that it should not be causeing my problem. They also said that they drove it and thought it was a missfire and that the egr needed to be replaced. i replaced all the plugs, wires and egr, and also checked the coils. all is good now right? Not at all. Still bogging down.

Please help if anyone has any ideas.

 

...Could be a clogged `Catalytic converter...They are known to clog `up & have the problems you posted about...
Have it checked out...Good Luck

 

Did they check the catalytic converter? I had a similar problem on my '01 and found there was a recall on the cc so I didn't even have to pay for it.

 

This. Have your cat checked. Along with spark plugs, wires, coils, fuel pressure, etc

 

Its you cat. To check it, remove the front o2 sensor and take it for a drive. It should drive run like normal

 

The cat can cause some serious problems with bogging the engine down. I know a guy that drove 1-2 years foolishly on a bad cat (car has NO get up and go). He was still passing emissions checks. After he failed, he took the car to an exhaust show, they found his cat was faulty, replaced it and the car runs great.

Also, am I correct in assuming it has the 3400 v6 under the hood? If so, those are based off the 3100 platform in my '94 Grand Am. The '94-'95 3100 Grand Ams are none for developing some issues around the EGR. The tube between the upper intake and the EGR will become blocked/plugged. I've corrected this with an old piece of speedometer cable (because it is very flexible and stiff to work with), and some carb clean. Take the EGR off, and try manipulating the speedo cable through that port and if you can get it far enough down to where it should be poking behind the t-body, the blockage should be clear. Use carb cleaner to help soak/loosen the blockage.

Following those instructions, don't be alarmed if the car runs crappy for the first few seconds when you start it (it's just clearing out that carb cleaner).

It may not be the source of your problem, but might be good to inspect. Another way to accomplish this is remove the T-body and work it from the inside out.

 

A clogged cat did the same thing for me. Replaced it and it is like a new car.

 

I have changed the plugs and wires and also the fuel filter. I also had to change the fuel level sensor because it was bad. Now i have a new problem. I start my car and it seems ok. As soon as I hit the gas car boggs down and dies. fun times i am having. i am saving up some cash and just going to have a shop look at it i think. if anyone has any more ideas let me know. sorry it took so long to repost.

 

has anyone checked the fuel pressure?

 

haha yes and no.. only a small hole for the backpressure to escape. and it uses the front o2 sensor to figgure if its running rich or lean so it can self adjust to stiocheometric air fuel mixture. that can make the car run rich by removing the front o2 sensor because it reads tons of air(thinking its from the cylinder)