I listed this in Exhaust. Maybe this was the better place.

https://www.thirdgen.org/techbb2/sho...hreadid=291263

Please check it out.

 

sorry to have dub post but i really need to solve this.

The EGR is not stuck. how can I check that it opens at the right time? I think I read that it opens when it hit 35 MPH, how am I supposed to check that?

I found a vacuum line that was disconnected. Its the line that Ts off from the Vac line that goes to the Cruise Solenoid and goes down to under the Batt. any ideas what that is supposed to be hooked up to?

Low Vacuum cases high HC doesn't it? If so why is that?

 

EGR mainly is for nox. You failed on the hc and co. You passed the nox, so your egr is probably ok. I'd do 2 things. First off, replace the o2 sensor. Next, replace the cat.

Next time you take it in for a test, be sure and drive the car around for about 20 minutes before taking it in for the test, to make sure the engine and cat are both fully heated up. If your engine or cat are not hot, you will fail for sure.

My IROC failed all three, hc, co and nox, by big margins, not even close. I got it fixed by replacing the o2, cat and egr. Now it passes the test with plenty of margin, but only when the engine and cat are HOT.

 

I replaced the O2 sensor before the test and drove the car to warm up for a good 30 min.
I was going to take the Cat off to see it was just an empty shell and its welded on.
so what I'm going to do is drill a small hole in the side and stick a pice of wire in there to see if its hollow. then I just put a screw in the hole. or replace the whole thing if its empty.

Thanks for your advice Tremo!

 

I'd replace the cat, run an emmission flush though the system then test again.