VX California and Federal Emissions Differences

[GasSavers_Crazy88]

I have a 1992 Civic VX. The check engine light was on when I bought it. The previous owner said he replaced the oxygen sensor, but he didn't know what else to do. After buying it, I started trying to diagnose it. I have a code 9 and 48. One relates to the lean fuel sensor, the other to the cam sensor. The car seems to run fine, but when I cleared the check engine light, it immediately came back on. My diagnostic tests point to a possible bad ECU, because it doesn't seem to be communicating. The oxygen sensor and the distributor check out good. According to the sticker under the hood, my car is a California emissions car. The part number on the ECU confirms this.

I posted my question on Honda-Tech.com. I was told that California emissions cars came with a 4-wire O2 sensor instead of a 5-wire, and that the Cali. cars had no EGR.

Well, my car has a 5-wire sensor and an EGR.

So now I'm confused. I know there are some VX experts (vxperts?) in here. Can anyone help me figure this out?

[GasSavers_Crazy88]

OK, I've received some info from others. Apparently in 1992 only ALL VXs came with a 5-wire sensor. The difference between Cali. and Fed. emissions was only the programming in the ECU. Cali. emissions had the lean burn disabled. Starting in 1993 Honda put a 4-wire sensor on Cali. cars.

So now my question is: If I replace my Cali. ECU with a Fed. ECU will the car now have lean burn?

[92VX]

Yes, you will have lean burn if all you switch is the ECU. That's what I did and the increase in mileage was worth it. I was scared something was going to fry because I couldn't find anyone that did it before, but everything has been fine.

However, get ready to feel a slight hesitation at times when the engine is getting out of lean burn. Not a big deal, but thought I should mention it. In my opinion I don't think the codes you are getting are related to the ECU.

[GasSavers_Crazy88]

Thanks for the info. I will go ahead and switch the ECUs. I realize I may still have check engine codes, but the better mileage alone makes the ecu switch worth it.