1989 Jeep Comanche Sportruck Emissions

[64chevy]

I'm restoring my Dad's 1989 Jeep Comanche Sportruck with the 4.0. Any advice on emissions? The truck was exempt from safety inspection emission testing in Oklahoma but must pass in Texas. The emission dash light is on. Also, any good OEM part suppliers? Thanks for your help!!

[Eagle]

The light on an '89 doesn't mean much. It is activated by a mechanical timer and it's nothing but a reminder to replace the oxygen sensor. Most of us have unplugged the light. The O2 sensor should be replaced about every 75,000 miles.

[ParadiseMJ]

I just finished bringing my "project" MJ up to CA emissions.

 

I didn't know what the PO had or hadn't done to it before (and it wasn't running), but when I got it there were a bunch of things ripped out of the engine bay. So I popped the hood on my XJ as a guide to go by.

 

I replaced the O2 because it looked like crap.

I had to replace and augment all of the emissions related vac lines as well as all the HVAC lines. I tested EGR function (push/pull)

I replaced the rollover valves on the fuel tank because they were dry/cracked/broken and both vac lines to the charcoal can.

I changed the oil, filled the tank and took it for a drive to get everything up to temp and running as clean as I could...and I bought a NEW gas cap.

 

It passed with great numbers. I don't think it would have passed CA smog if I hadn't done most of the stuff on that list.