Does anyone in Chicago have a muffler and cat/bypass I can borrow?
 

Diagnosing a problem mentioned in other threads, and I'd like to do an A vs B with the exhaust and swap out the muffler and cat. I have a stock muffler and non-functioning (so I was told by the PO) cat. I have a wideband O2 sensor so I'd need something with a bung in it, but swap pieces don't have to be stock. Simply removing what I've got is going to be so loud as to be useless, most likely.

If anyone in the Chicago area has one or both that I could borrow for a weekend, I'd be most appreciative.

My 82 SC has a stock muffler and a stock cat that has been absolutely gutted. Nothing in it. Still have the O2 sensor installed and it is working fine with the Lamda system set to the proper CO. It's really not much louder.

I may not have been clear enough - I want to swap to see if my exhaust is contributing to the issue I'm having. I could just remove the exhaust, but then the engine will likely be too loud for me to tell whether the condition has changed. Idle might be OK, I dunno. Current exhaust setup on the car is the same as yours.

I have both for you to use in a test. In Barrington.

@Gadsby - thanks. Friday I noticed a possible leak at a gasket so I'm going to test for that first. If that doesn't show a leak, I'll take you up on it and PM you this week.