Hi guys, I did a complete search and didn't find this anywhere.

My 89 Monty just failed emissions test (NOS extremely high) and I was told it's either the EGR valve or catalytic converter.

When I connect the EGR valve it kills the engine, but when I disconnect it, it runs smooth again. I tested the EGR and it holds a vacuum, so I don't know how to troubleshoot this.

Should I just pull all the vacuum lines except to the distributor or what? Also, if I mess with the distributor, where does the vacuum advance come from when I accelerate.

Sorry for all the questions...

NOTE: I have a Weber installed so not all vacuum lines are needed, but I followed the shop manual and have 90 percent lines correct. <img src="/forums/images/graemlins/confused.gif" alt="" /> <img src="/forums/images/graemlins/confused.gif" alt="" /> <img src="/forums/images/graemlins/scared.gif" alt="" />