2002 Monte Carlo SS Poor Acceleration

I have a 2002 Monte Carlo SS and just started having some engine troubles. Under medium to hard acceleration the engine hesitates or chugs for a few seconds and the RPM's drop down and bounce back up a couple of times before it will take off. It also does this when climbing hills. The garage just replaced the throttle position sensor but this had no effect. Does anyone have any ideas or experienced this before?

I'm having similar problems, I'm going to get my Throttle Body cleaned soon. I'll let you know how it turns out.

Maybe change the fuel filter, check the fuel pressure coming from the pump. Good luck finding the problem

Check the catalytic converter. It's known to go bad on W-bodys with the 3.8L . I think GM made the warranty on it 120K mi/12 years too because of the high rate of failures. It also won't trip an SES light, so get it back-pressure tested.

Thanks for your help guys. I'm taking it in again this week, so I'll let you know how everything goes.

Check the catalytic converter. It's known to go bad on W-bodys with the 3.8L . I think GM made the warranty on it 120K mi/12 years too because of the high rate of failures. It also won't trip an SES light, so get it back-pressure tested.

Who do you need to talk to about getting that warranty honored?? Just take it to the dealership or what?

I'm taking my car in on Thursday thehammerhunter so I'll let you know how it turns out.

Having the same exact problem, would appreciate whatever info you will find out.

PS General Question - I got 01 Monte SS, 147K - What should be checked out, changed, etc.

Thanks

If you just got that car.. i'd do a complete tune up.

Check the catalytic converter. It's known to go bad on W-bodys with the 3.8L . I think GM made the warranty on it 120K mi/12 years too because of the high rate of failures. It also won't trip an SES light, so get it back-pressure tested.

where did you read/hear about this warranty? I recently bought mine (3.8L) and it made no mention of a warranty of any kind.

GM sent original owners of the affected model years (i think 2000-2002) of Buick Regals, Chevy Monte Carlos and Impalas (I think the Pontiac Grand Prix too) a letter stating that they extended the warranty on the catalytic converter to 120K miles. If you take it in to be tested and the dealer says it is ok, that diagnostic charge is not covered. However, if it is found to be defective, then they won't charge you a dime. For more info, see the Impala section of this forum.

EDIT: see http://www.automotiveforums.com/vbulletin/showthread.php?t=630925 that thread for more details. I believe a copy of the letter is placed there, too. There are many many many more threads along these lines, so search for more details.

Check engine light came on, comes out to be MAF sensor, which i did replace about 5 months ago,

I had the car ever since, so just trying to think what else I should check into.