Ok, guys I would apreciate your input on a problem I have with my 2001 Zx3. The only modifications I have done are AEM Cold Air intake and some exhaust work. My cat has been punched and my muffler and resonator have been removed and a straight pipe added with a resonator. The problem is that when my car idles down it doesnt slow down. It just dies. If I give it some gas to prevent it from stalling it idles funny by bouncing from 300 rpm to 1100 rpm. Also, seem to have lost a significant amount of power. Could this be a lack of backpressure or an O2 sensor problem?