I am having trouble with my 97' 2.4 Cavalier trying to stall out, or even die on occasion.....

Sometimes it will try to die either when it is idling or at very lite throttle when accelerating form a stop light or stop sign. If I give it a lot of throttle it runs good. But, when I engage the clutch or put it in neutral to stop or turn and the throttle drops back around idle, it tries to die or at least stutters really bad. Once again, if I "feather" the throttle while it is throwing it's fit it will come out of it. I have changed my TPS, plugs, coils, fuel filter, and air filter. I am going to check my IAC valve, and IAT sensor after work.

I have a HO 2.3 manifold with a HO 2.3 TB that has been on my car for almost a year. IF my IAC valve is faulty, do I need the one for a 2.3 or 2.4?

Is there anything else that I might need to check?

I just had some exhaust work done and now my downstream (after-cat) o2 sensor is tripping my check engine light. Could that be part of my problem? Isn't that o2 sensor just there to tell you if your cat is working good or not? Does that sensor have anything to do with fuel delivery, spark or timing?

ANY suggestions will be GREATLY appreciated!! I am tired of worrying if my car is going to die in heavy traffic, or when I am trying to turn a corner, or when I am trying to pull into traffic!!!!

I "searched" and found one of my answers...... "USE 2.3 SENSORS ON THE 2.3 TB"!!

Any other sugestions, or comments?

Downstream O2 sensor is only there to double check your emmission output. OE cats are notorious for cloging up. You may want to try an aftermarket high-flo cat in there. You'll need to have a sensor bung put on it so you can put the sensor back on, staying legal.

Thanks for the heads up. But, I already have a 2.5" Hi-flow aftermarket cat installed on my car. I have had it for a little over a year now.

I have narrowed it down to what the problem is..... It IS the IAC valve. I took it out and cleaned it really good and know it is running perfect! I am glad that I was able to clean it to make it work because the new one was going to cost my $75 from Autozone. It no longer stutters, shakes, or shimmies when I am driving.

Thanks, and I hope that some other people read this post that may be having the same kind of problems and it can help them remidy there stutters too!!