- Joined
- Jul 20, 2001
The car may pass an idle test without a cat, but it looks like Illinois smog test type is I/M 240 (for 80 and newer). That car may be lucky to pass that type of a smog test even it the cat is installed. I/M 240 requires the engine to be running almost perfect. The Nox portion of the test will be the hardest part, as the car is accelerated to 58mph on the dyno (from almost a dead stop). This is the position where I/M240 test for Nox.