Strangely, the last FL readings were the 66/.00/14.1. He must have done something after the high reading. Thankfully the IL-DOT does not charge for emissions testing. A nice woman at the DMV told me that if you accumulate enough $$$ spent trying to get you car up to snuff, and there's nothing actually wrong with the emissions system (via mechanic affidavit) they will waive testing. She also drove a 1984 300SD and was extremely sympathetic.

A full new exhaust system is in the works, and I hope I don't have to get it to pass this test. I've been holding off on getting an exhaust system out of this fear that they car (being euro with no US emissions related hardware) will not pass IL testing no matter what. That means selling the car with what will surely be a >$1000 new system. I have to get a euro exhaust then have universal catalytics spliced into each side. US made exhaust is apparently completely different and not interchangeable.