Phoenix79

I've been reading up on emission testing for IL at the main Emissions site for IL. Since my car was built before 81 I won't have to take the dynamometer, but I do have to pass the basic idle test. The site doesn't go into further detail as to what the basic idle test is...

I plan to take my stock 79 and install true cual exhaust with headers. Some people from IL have yet to ever have their cars tested and so far I haven't had to have my car tested during the 6 months I have owned it. But if I do...I would like to know what I'm up against. So back to the question, what is the basic idle test? I can infer that the car is hooked up to a machine and while idling is checked...but will dual exhaust complicate the matter and cause me to fail the test right off the back? That's my only concern. I've heard of visual tests but the IL Emissions site does mention it...

zwede

The idle test is pretty easy to pass. They will check CO and HC. Some states also check NOx. Even pretty radical cars can pass by increasing idle speed to the max allowed, retarding timing and leaning the mixture.

Problem is you would flunk the visual. You can't install dual cats on a car that came with a single cat.

82dukman

One tip I learned here in PA. If you can, take the car out on the interstate or open highway and run it. Get the motor nice and hot, blowing out carbon and then go to the test(after about 20 min.). You'll be suprised how low everything becomes.

NK77

I just had my 77' L82 tested at the Schaumburg facility and it passed with no problems. I don't have any cats on a true dual exhaust and they didn't say anything. I also have a non-emissions Holley (quadrajet replacement) and a performer manifold and headers. I retarded the timing a little and used regular unleaded gas. I never thought it would pass, this was my first time through an emissions test. They did check the gas cap too.