yotajakes

so ive got an 88 22re federal emission motor. I was randomly throwing an egr. some drives it would throw the code, others it wouldn't. so thinking about what would tell the ecm to throw the code when there is nothing electrical to monitor the egr function (except cali emission trucks), I dug into ecm part numbers and found that po changed out the ecm and just so happens to be a cali part number.

so my question for any of you gurus out there, what is the difference in the ecms? minus the egr temp sensor. ive read that it should also be picking up the 2nd o2 sensor for the cali trucks, but my truck being federal only has the one and doesn't have the harness for one, but here is the strange kicker, it doesn't throw an o2 code. just the egr.

I'm wondering if this mix up on ecm part numbers could be causing some of my other minor issues. low low idle at cold start, then higher idle once warm. never really stable when I'm out driving around. cant set it at a constant 850.

any input though on the ecm differences would be greatly appreciated. I'm going to start looking for the correct ecm in the meantime. mostly just curious.

854x4

What part number computer do you have in the truck now and what code number is it throwing? Also rear o2 sensor weren't used until the 90s on these trucks.

89661-35110 Federal
89661-35130 Cali

yotajakes

my current computer is the 35130 as per the part number sticker. the code that I get intermittently is 71.

didn't make sense to me as to how that would throw a code till now. because I have no egr temp sensor or connector and everything with my egr system is functioning properly. ( checked everything multiple times due to the code).

92ehatch

If the ecu wants that sensor then it wants it. I think when people eliminate egr they place a resistor in the wiring to compensate for the missing sensor.

You can do that but will have to probably add the wiring and have the correct pin out. Doable it is. Worth it? I would just get the right computer
https://www.yotatech.com/forums/f2/if-you-remove-egr-fake-sensor-63182/

yotajakes

Ya, adding the wire and everything would probably be more of a hassle. I could live with the light, the egr itself is functional. I'll keep looking to see what else is the difference between the computers. Curiosity. .