I hope someone can help me. I bought a 99 Blazer 4x4 LT recently and have not been able to pass emissions with several categories displaying not ready to be tested. I have driven it a couple thousand miles since first attempt but OBD is not cycling through. No "dummy lights" have appeared and a Chevy dealer did a performance analysis yesterday and no current or past codes in system. They said to keep driving it but shouldn't it have reset by now?

 

Rick,
one possibility is a blown or missing fuse. : I took mine to autozone prior to the Mass inspection and found the scan wouldn't complete. I recall the fuse was in the interior box and I recall though not sure with this, it being either to the dome light system or the cigarette lighter. In any event, I replaced the fuse and the scan took. I suggest taking it to autozone for a freebie prior to going to the inspection station as you should be able to confirm whether it's good to go.