Which years' ECUs are compatible with which other years? For instance, my 94 ECU would work in what other cars, and which other ECUs would work in my car? I assume there are differences between hi/lo port and OBD I/OBD II. Any information appreciated.

I figure this question has been answered but the search function is currently AWOL, so help me out here. Planning for future upgrades.

AFAIK, there's no difference 'tween the hi/lo-port ECUs. but the OBD part is what is important. the 98+ ECUs are not the same as the 91-97. the 94-96 G20 ECU will work in the 98+ SE-Rs, but results in a CEL.

I think the '94 SE-R has a unique ECU. The '91 - '93 has the AIV, which the '94 does not. I would ask JWT about this though.

Originally posted by eric96ser
I think the '94 SE-R has a unique ECU. The '91 - '93 has the AIV, which the '94 does not. I would ask JWT about this though.

The AIV is not an electronic sensor, but rather a air flow contraption. It should not effect the ECU in any way. As a matter of fact, if you do it right, you can remove all of the AIV housing crap w/o any issues.

quoted Ben Davis...
This is the AIV hose. On all 5-6 AIV systems I've removes, of them had a
LOT of water in the AIV valve on the front of the valve cover. Just remove
the system.

1. Remove the line that goes to your airbox and duct tape up the hole on the
INSIDE of the airbox. It's nice and flat in there so the tape should stay
very well.

2. Remove the AIV valve and small resonator box on the front of the valve
cover.

3. Remove AIV hard line going into the exhaust manifold. Cut it off with a
hacksaw or something close to where it screws into the manifold. Hammer the
place where you cut flat and then fold it over about 3 times. Should end up
looking like this http://www.sr20deforum.com/geekout1/DSC00009.jpg . Screw
that back into the exhaust manifold which effectively plugs that hole.

4. Trace the small hard line back that was connected to the AIV across the
valve cover to a vacuum line that goes into the intake manifold. Remove the
hard line and plug the hose with a bolt/screw.

Voila! No more AIV system and no more water in your intake. :)

Ben Davis
AIV system removal expert

Originally posted by NismoPC


The AIV is not an electronic sensor, but rather a air flow contraption. It should not effect the ECU in any way. As a matter of fact, if you do it right, you can remove all of the AIV housing crap w/o any issues.



Under the TB, there is a sensor for the AIV system.

Come on out there, does anyone have an answer? Andreas? Anybody?

Originally posted by Rittmeister
Which years' ECUs are compatible with which other years? For instance, my 94 ECU would work in what other cars, and which other ECUs would work in my car? I assume there are differences between hi/lo port and OBD I/OBD II. Any information appreciated.

I figure this question has been answered but the search function is currently AWOL, so help me out here. Planning for future upgrades.
Depending on which type of motor you have-high/low port your wiring harness should be different.
OBDI-Blue connector to ECU-definitely in 91-93
/example that is different-stock revlimit higher
OBDII-White connector to ECU-definitely in 95-97
/example that is different-stock 109 speed limiter
94:confused:- depends on your harness
JWT probably configures them the same, but IMHO there are some differences between them.

Originally posted by NismoPC


The AIV is not an electronic sensor, but rather a air flow contraption. It should not effect the ECU in any way. As a matter of fact, if you do it right, you can remove all of the AIV housing crap w/o any issues.



On the high port motor, if you remove the AIV you will negatively effect emissions. The ECU definitely has a say in the operation of the AIV. I removed mine and had JWT program in some controls from the '94 and later ECUs that compensates for the lack of AIV.

Steve