ok here it goes 97 cavalier z24 so most of youguys know it has the 2.4 with a 5 speed.i just had the whole exhaust done and water pump.i have put both o2 sensors in.i have a problem with it idleing,when it get warm and is just idleing sounds like there is a vacum leak .me and the mechanic searched every where looking for it.can`t find one.if i am driving there is no problem till i stop and its idleing at a light.we reset the codes cause it said it was the o2 sensor in the manifold.we replaced it and its still doing it.the cel hasn`t come back on yet,so i don`t know whats causing it.any ideas,i replaced the map sensor and the hose to it.any help????????????

I have seen the diaphragm on the EGR valve leak. just pinch the vacuum line to it and see if the idle smooths out to check it. also make sure the intake manifold gasket has been checked for leaks.

figured it out timing jumped one tooth all is well and fine now