Well, the limits are pretty tight, for ehample my 91 Caprice wouldn't pass, so i just put it on the dyno, and adjusted the timing, pulled out the EGR, and eventually she passed. I know, "cheating is wrong". Cars that are exempt from E-tests are cars that are 20 years old or more, so for example, cars that were born in 86, are exempt from the test. I want to buy a 83 Cutlass Supreme after I'm done with the thunderchicken.