fuelforwar

The only other thing I can think of would be the ej25 o2 sensors just read different than the ej22 sensors. If that's the case I'll need to hunt down the right o2 subharness and order new sensors.

So I made a little head way on figuring this out. Tracing all the pins back from the e1 clip to the ecm, there's only one difference between the ej222 and ej251. The #9 pin on the ej22 bridges with the #6 pin, ties into the c3 pin at the ecm, and the whole branch is fed from the main relay. The #9 pin on the ej25 bridges with the #6 pin and is fed directly from the main relay. It doesn't tie in to the c3 pin at all. On the ej25 loom the c3 pin ties into the tail/illumini nation relay and a lighting switch. I'm trying to figure out if I can just tie in a wire between these, or if it would cause a problem with the other system attached. I can't imagine having two positives crossing would be a good idea. Trying to figure out the best way to do this. I drew up a rough sketch to try to illustrate this. If the voltage is the same and consistent it might be fine, but I'm not sure exactly the function of what the c3 pin does/needs. I did pull the sub harness and tested all wires for shorts/breaks. Everything is fine on it. I'm going to test the loom from the e1 plug to the ecm next in case I'm missing anything else.

That would be great and I'm hoping i get that lucky.

Sounds good, I'll just keep digging through fsm's instead of trying to look up individual diagrams just on that circuit. So far I've only been able to find 4 pin diagrams that are a different color then my harness. I wish I dug into this more before I scraped the car. I'd have just chased up the old wiring and replaced it into the new car in the same layout. I even had the whole dash out of the new one to replace the heater core, so that would have been a prime time. That's just the way stuff rolls sometimes tho. Thank you for the info!

I appreciate the info. I've been driving the car for the last couple months and everything else seems to be working fine except the 02 sensors, but I'll cross reference where I can to confirm. My gas mileage has been been between 18-20mpg so I'm sure it's due to the fuel trims being off because of the 02 sensors. Where's a good place to find a digital fsm? Basic Google searches on year make and models gave me a mixed bag of results and diagrams.

Thanks for the link, I'm going to look through this and hopefully find what I need. Sorry for the confusion on my choice of words with swapping. I never stated that you told me to change the engine. I'm saying I don't have the ej25 that originally came in the 02 impreza to pull parts from for the ej22. To do it the way you explained I would need to hunt down these parts from a junk yard or buy them new. The 02 impreza was just a car with the drivetrain installed. Would it be more efficient to do this or rewire the 02 circuit. I just did a full rebuild on my ej222 before the wreck. I'd like to keep as many new and restored parts as possible before putting used ones on.

The differences in the looms seems to be my current issue. Both engines are phase 2 non turbo with manual transmissions. My main issue with this was I never had a donor ej251. The 2002 impreza was just a roller. I transplanted the complete ej222 out of the 2001 impreza. At this point your saying it would be easier to go out and buy a complete intake manifold with the works, cam gear, and ej251 eco, then it would be to rewire the 02 sensors? That seems like it would be more time and cost consuming then chasing and repinning some wires.

My biggest concern is, it looks like the 02 is a wide band 02, and the transplant engine was using a narrow band sensor. Everything I look up tho shows the 02 impreza should be a narrow band. However my scan tool shows it getting 3.7v and a lamda reading of 9.999. If it was narrow band it should be showing voltage of .1 to 1.0v

I'll try to clarify this, the car everything is installed in now is an 02 impreza wagon T.S that originally had an ej251. The donor car was 2001 impreza wagon L with an ej222. I swapped over the ej222 and the computer for the one that was with the ej222. The main harness from the engine bay to the computer and 02 sensors are still from the 02 impreza. I replaced both front and rear 02 sensors with new ultrapower brand ones from rock auto.

Hey everyone. Been searching without much luck for some info on an 02 sensor problem. As a little back story, I spent a year rebuilding a 2001 impreza wagon L with the ej222. After having it back on the road I was in an accident that totalled the vehicle. A couple years later my neighbor made a deal with me and gave me a 2002 bug eyed impreza that had a blown ej251. I swapped in the ej222 as a complete unit (didn't swap intakes or anything), swapped the computer, and the exhaust. Engine starts right up but I got multiple codes for the 02 sensors. Swapped both of them out but continue to keep getting P1132, P1133, and P1139. I've inspected the wiring and it seems to be fine. With a test light I'm getting power to the plug that feeds the 02 sensors. I noticed the 02 sensors are different between the two vehicles. On my 01 it was a 4 pin, and on the 02 it's a 6 pin, but the 02 sensor only has 5 wires. Do I need to repin the plug or change out the wiring to my sensors? Been struggling to find the right diagrams that matches my wire colors. Any help or input would be greatly appreciated. Thanks