I have a 2003 Chevy Cavalier and am having quite the issues with it. It was pulling codes for the downstream O2 sensor and a misfire. We replaced the spark plugs and went to have the o2 sensor done when we found out that the last person cut out the catalytic converter and just put on a straight pipe and I don't have a downstream O2 sensor and that's why its pulling the code. About 3 weeks ago my car started idling really low and now its idling low and nor accelerating like it should it won't accelerate over hills and is going through 2 times the amount of gas as normal. Due to stop and go traffic it stalled out on a very busy road. You can also smell what smells like gas usually when Im trying to get up to speed since I have to floor it just to get to 25 mph. Someone said it might be the injectors but I would hate to put $400 just in injectors for that not to be the problem. We put some lucas treatment and premium fuel in it.
Does anyone have any ideas to what this might be or gone through this before?

 

Test the throttle position sensor, chances are that is the cause of why you have to push the accelerator pedal so far to get the engine to speed up.

Part 1 -Throttle Position Sensor (TPS) Test: GM 2.2L (P0121, P0122, P0123).

 

Where do you live? I am parting a 2003 cavalier and have ay part you need including converter. Ernie ern.sue@verizon.net