My 1995 4Runner Limited failed smog because of high NOX measurments. Results -
M1 15MPH 508 - MAX ; 1073 - ACTUAL
M2 25MPH 761 - MAX ; 914 - ACTUAL

The EGR is suspected and I am not sure that it is opening as it should. Until I read Mike D's explaination of what the EGR does in response to Michaelangelos question posted last November I didn't have a clue. I know where it is located but if I wanted to troubleshoot this part, or even changed it and related hoses where would I start? The tech did find that there was no vacuum when he disconnected the tuube going into the egr, but he said that it could be a number of things. I am trying to avoid paying the smog tech $90 to diagnose and then $65 to $95 for the part and Lord knows how much I'll get gouged for labor. Thank for any assitance.