Hi all, I am having a problem with my wife’s Monte Carlo SS. It will start and run OK but will not accelerate above 3000RPM, it just dies down and sort of holds the 3000 RPM's. It will do this in Park and under load, (drive, reverse). I changed the fuel filter and it was hard to blow through thought that was it but did not help. The problem began while she was on the interstate, first the check engine light came on, then later it started to just die down when she mashed the accelerator. It also makes a noise like it is backfiring but it does not sound like a normal backfire. Any suggestions would be appreciated.

6 cylinder?

You might have the catalytic converter checked.

It's your catalytic converter, and your car if it has less than I think 90k or 80k or maybe 100k (I forget had same issue on a 01 Alero) I'm not for certain call GM and ask them but if it's under that mileage then your car is still under warranty and they will replace the catalytic converter because it's considered part of the emissions system and that's covered longer than the usual 3 yr 36k warranty we got back in the day before 10yr 100k's came along. But it's most certainly your catalytic converter, because I've been thru this and my car had I think 80k or so miles & GM fixed it for me.. I was without a ride for a few days, but at least I didn't have to pay for it cuz that's pricey to get done. But like you I went thru changing a fuel filter and all. So that's what it is, I just hope your car is under the mileage required for GM to have to fix it. :)