P07 ECU differences for VX - CA versus Fed
 

Okay, so I bought a 1992 Civic VX that has been messed with (prior B18 engine transplant) and put back to stock. My problem is I can't verify if I have a CA car or a Federal car... the engine wiring harness looks to support a 5-wire O2 and that is what is on the car now but I get a code 48 CEL. I bought a new O2 and the CEL is still there... so I dug a little more and found out the ECU is a CA version P07-L00. Could this be causing the CEL 48? I am trying to source a Federal ECU now to swap in. I also noticed the power is off in the high RPM's and that I have to downshift on hills on the freeway. Hoping the P07-A00 ECU will fix all this... :D

David

So I guess the engine is now a D15Z1.

Does your dash cluster have an SIL (shift indicator light)? This would be a clue that you're Federal. But of course the cluster could have been swapped.

You can also check the sticker under the hood. On a CA car, it will say something like this: "this vehicle conforms with US EPA and state of California regulations." But this is also not definitive, since hoods can be swapped.

The other two signs of a CA car are the ECU and the O2 sensor. Also the engine wiring harness, which will correspond to the O2 sensor.

In '93 to '95, the CA VX had a 4-wire O2 sensor. But in '92, the CA VX had a 5-wire sensor, just like Federal. But all CA VX ('92-'95) came with the CA ECU, which does not utilize the 5-wire sensor and hence does not support lean burn.

I don't think it should, because I think you have an ECU and O2 sensor consistent with the way your car was equipped at the factory.

That seems like a reasonable move, and I suppose you might as well do that first before you worry about looking for other issues. I think there probably is another issue somewhere, but you might as well start with installing the Federal ECU, since you want to do that anyway.

That's not right. Power should increase nicely as RPM goes up.

Top gear is really tall. So if it's a steep grade you might have to use 4th gear instead of 5. Especially if there's any extra cargo in the car, or other issues, like a stiff headwind.

I have a feeling there are other issues, but they might be very basic things.

In the Helms service manual, p. 11-38, there's a troubleshooting procedure for CEL 48. You should probably go through those steps, but I suppose you might as well wait until after you have the new ECU.

Thanks Monroe, as you mentioned this car has been through alot. The hood is not original and neither is the motor. The harness looks like one for the 5-wire so I figure may as well go Federal. Will let you know once I find an ECU to swap in. ;)

David

It's great that you are bringing a VX back to life. If the body is basically solid, then I think it's probably a very worthwhile investment. VX prices are climbing.

The biggest expense in converting CA to Federal is the O2 sensor. But you already have that (or two of them, even). And you already have the Federal engine wiring harness (since your CA VX is a '92), so that means there are no wiring hassles to deal with. So giving your car a Federal ECU seems like a smart move.

Just keep the old ECU around in case you run into smog issues.

On eBay, here's a VX ECU that just sold: 320259995128 (just put that item # in the eBay search field). The price was kind of high.

Here are two others that are for sale:
250257491801
200230419946

Thanks for mentioning that Monroe... I was the "high" bidder on that one but needed the ECU ASAP. ;)

Hey, I do not have access to a Helms manual... any chance you could send me over those details on troubleshooting the CEL #48? Thanks,

David

It's not hard to find on the web. Do a google on words like this: Helms factory service manual Civic 1992-1995.

If you can't find it, let me know.

Okay, I tried to find it but the only stuff using that my search was torrent downloads I can't get and a corrupted .pdf. Any chance you could post the troubleshooting for me? :(

David

I sent you a PM.