Just because Mitsu has different part numbers doesn't meant that they aren't the same sensor...might just mean that the cables are different lengths.

The Denso part number is the same front & rear.

http://www.amazon.com/Denso-234-4210...-Oxygen-Sensor

 

Man those denso's are like 400.00 + a piece... that's a bit much I would say. What makes them do any better than a universal for 50 or 100.00? I mean if it reads it, it reads it.

 

UPDATE: After soaking the front o2 sensor in gas for about 40 hours or so, I installed it today. I started it up and the idle seemed to be a bit better, it wasn't jumping around quite as much.... as it sat, it did begin to jump around a little more. I can't judge it based on that, so I took the car out, ran a few errands and then did a pretty good 3rd gear pull to blow any loose stuff out that might have been left in there. When I returned home, the idle was normal... I didn't let the car run long, and the SES light was still on, but I know it sometimes takes a bit of time for the ECU to reset stuff like that, so I will wait a few days and just do some normal driving and see if the light goes off. If not, ... well yeah i'll be a bit aggitated, but it was a basically free way of finding out for sure it wasn't going to work. The AFR readings however DID seem to be closer together, bouncing from low 14's to an occasional low 15 which I thought was an improvement and showed that it did at least do something to help.

Now, if I do have to replace the sensor.. I have a friend that works at a local auto parts store, and they don't actually have a sensor listed for the 08 Evo... he said he did pull up an 06 universal 4 wire and I don't really care about cutting wires ... sooooo... would that one fit does anyone know?

As i've asked before, a sensor is a sensor and they all get hot and read what the PCM tells them to right? He would likely let me bring it back if it didn't work, and it's 43.00 so it's worth a shot if I have to go that route. I know a few here have suggested swapping the o2's, but i'm concerned that either something won't be right plus the rear o2 wire seems to be MUCH longer than the front... has anyone here swapped them before?

 

UPDATE AGAIN: I swapped the front and rear o2 sensors tonight and so far I don't have any codes, though the idle is still sort of jumping around. I let it idle for a good 5 or more minutes and then took it about a mile or so up the road, that isn't an easy swap to make. I had ordered the sensor and when I get it, it's the wrong one. It's for a non turbo, california emissions vehicle, I even called Denso directly and they confirmed it... idiots.

 

I ended up not even needing my front o2 i ordered. Used it for one day and took it out lol. Found out my front o2 wasnt going out. Something else was triggering the code.

 

did you figure out what? Tightened and double clamped all of your IC pipes? Checked the vac line to the intake manifold? They seem to blow off a lot.

 

Disabled my o2 sensors. I run in open loop. I have 2150cc injectors, they dont like my o2 correcting them.

 

I didn't know you could disable them like that?

 

You can turn them off and run open loop by playing with the cross over points.

 

Or just unplug them.

 

sh#t, so I could have just turned them off and not had to swap them out?

 

UPDATE YET AGAIN: threw SES light... haven't checked what the codes are now... perhaps they are to the rear of the car... the last time I tried to check them, I got an error connecting to ECU message and it wouldn't read them, though it logged and read everything else fine... how do I disable these FU#KRERS??????????

 

well its pointless doing anything without finding what the codes are...

 

i'll have to get my friend to bring home his code reader tomorrow and post them up... MAYBE it will be codes for the rear and the front will be ok.

 

Tephra, well none of the codes directly mention the front 02 sensor. It is several p0420 codes.
P1290 fail safe mode (lost of controller area network data).
41417
C121C Torque request sugnal denied.

Also, the target idle speed is 703... I don't understand quite why that is so low?