Hey everyone...I have a 1988 YJ, 4.2, nuttered, Motorcraft 2100, Team Rush upgrade and it failed Az emissions with high NOX. The readings are as follows:
My Vehicle / Applicable Standards
HC 2.01 / 3.00 Pass
CO 5.84 / 25.00 Pass
NOX 9.59 / 4.50 Fail
Any ideas what I should do to make that NOX pass? Please help.
The little booklet they gave me has a few things listed that may cause that problem:
* Removed, plugged or malfunctioning EGR system (mine is still on)
* EGR valve
* EGR exhaust gas ports, lines and passages (what is that?)
* Abnormal engine operating temperature (mine doesn't overheat or anything like that)
* Air management system malfunction (what is that?)
* Lean air/fuel mixture (mine runs great....except when it warms up, it idles at around 600 rpms...pretty low I think)
* Catalytic converter efficiency (what's that mean?)
* Over-advanced off-idle timing (I don't know where mine is set at, but it runs really good)
It also failed the pressure test, but I think I know what the problem is there. When I filled up with gas the other day, I had some gas "overflowed" on the top of my gas tank. I think it's the rubber grommets on the vent lines to the rollover thing. I ordered those grommets online, but I'm going to see if I can find some at checker auto or autozone.
I have about 2 1/2 weeks left on my temp tag, so I need to get this through emissions sooner than later.
Thanks in advance...