ok i have a 2001 alero with the 3.4l in it. the car will not accelerate at all, it will also not go above 4000 rpms. when its in neutral or park it revs fine, as soon as i put a load on it it will not accelrate. i have the throttle down all the way and it gets to 4000 and wont shift untill you let off the gas and then it will go to the next gear. it will only get to around 50 mph as well.


I have changed the spark plugs where were completely annihilated, and the fuel filter as well. i took it to a dealership and they said the cat is clogged. so we cut off the exhaust and it still does it. ithe only pipe left is the one off the headers to where the second cat is. so could the first cat be clogged or a bad 02 sensor? can i just gut it out or do i have to buy a new one?

A bad 02 sensor will light the check engine light. It sounds like a cat. My brother's Cutlass did the same thing, a new cat fixed it.


Gutting it will probably cause a check engine light due to the rear 02 sensor, and is probably illegal anyway due to emissions control laws. Buy a new one.

I like to change o2 sensors every 2 years. Keeps my gas mileage up.
While im there I check the whole exhaust.