Running Rich

I have a 93 Corrado with a 2.9L. I was involved in an accident a few month back and have been having this problem ever since. The car runs about 50 -100 rpms below normal idle and it runs way rich. I get a CEL saying that I have an O2 sensor fault saying overregulation. I have changed the O2 sensor, the MAF, the ISV, plugs and wires, blue temp sensor both knock sensors. Basically I am down to thinking I have an exhaust leak between the block and cat but I don't hear anything but I do smell it.

The O2 fault doesn't come on till the car has warmed up quite a bit. Once the CEL comes on, the idle somewhat stabilizes. It is still low but doesn't bounce so much that the car stalls.

I guess what I'm asking is, will an exhaust leak or even a clogged cat cause these symptoms?

I'd try a new coolant temp sensor, they're cheap & easy to replace. To test the sensor w/ohmmeter on the two sensor pins you should get 2000-3000 Ohms cold & 200-300 Ohms at operating temp.

I have a 93 Corrado with a 2.9L. I was involved in an accident a few month back and have been having this problem ever since. The car runs about 50 -100 rpms below normal idle and it runs way rich. I get a CEL saying that I have an O2 sensor fault saying overregulation. I have changed the O2 sensor, the MAF, the ISV, plugs and wires, blue temp sensor both knock sensors. Basically I am down to thinking I have an exhaust leak between the block and cat but I don't hear anything but I do smell it.

The O2 fault doesn't come on till the car has warmed up quite a bit. Once the CEL comes on, the idle somewhat stabilizes. It is still low but doesn't bounce so much that the car stalls.

I guess what I'm asking is, will an exhaust leak or even a clogged cat cause these symptoms?

How are the RPM's driving, does it rev up then not go any further, usally that is a sign of a plugged cat, that and that wretched egg smell.