Thread: 95 B14 SE-R: OBD1 or OBD2???

Hi guys,
I've tried doing a search (on both forums) and could only find old threads on the subject and no definitive answers. I've got an early VIN 95 B14 SE-R MT and would like to switch to a G20 MT ECU to get rid of the speed limiter and raise the rev limiter, but all 94-96 G20 ECUs seem to be OBD2. I've always believed my car to be OBD1 - I have both OBD1 and OBD2 ports (one under the dash and one next to the fuse box) and have always used the port next to the fuse box (this is the OBD1 port, right?) whenever I've pulled fault codes on a CONSULT.

I guess first question is... Is my car OBD1 or OBD2?

Second question is... Can I install a 94-96 OBD2 G20 MT ecu in my car?

Thanks for your help.

Davin

It is OBD II. That ECU will work nicely in your car. I, also, own a 95 200SX SE-R. One of the first things I did was get a G20 ECU. The timing is a little bit more aggressive on the G20 ECU I think. (prob because of the weight in the G20 and it works well in a 200SX)

From what I understand, you can only pull codes from the Consult (OBD I) port. The OBD II port does nothing, I guess. Just there for show, perhaps.

Sweet! Thanks for the info. That's such a strange way for Nissan to design it. I also forgot to mention that when I used the CONSULT, it was running OBD1 software. I guess it doesn't make any difference?

Now comes the tough part... finding a G20 MT ecu!

BTW, will swapping in a G20 ecu trigger a CEL?

As long as the OBD II ECU has nothing to cause a CEL, it will not throw one.

OBD II is a picky system and the dumbest crap make a CEL go off. I have been fighting with an EGR code for weeks now and I cannot figure it out. It is not the temperature sensor and the valve is not clogged so I have no idea what it is. Maybe the warmer weather makes it weird, I dunno.

Either way, a G20 ECU is a nice cheap upgrade to remove the speed limiter and I guess increase the RPM limit. I noticed the car was smoother at idle, decel, and light accel. Overall, I was pleased with what the G20 ECU brought me. (Although pointless to rev that high when you have stock cams)

I used the G20 ECU with an air/fuel piggyback system and I got decent results for what I was using.

In my opinion OBD-I FTW!

^ What alf said.

OBD II is f*****g stupid.

You are lucky because even though our 1995 cars have the OBD II system, as far as I know, no state runs an OBD II test on our cars. They would run the old style dyno sniffer rolling test. That makes me easy to just put an OBD I ECU in the car with a stepdown harness and stops stupid codes from popping up.

Couldn't agree more. Less stuff to go wrong.

So if I install a flywheel with the "incorrect" number of teeth, my 95 will trigger a CEL?

Yes it will.

Mostly because OBD II is stupid. Actually that is 100% of the reason.

Huh... All this time, I thought I had OBD1...