I currently got my full techworks exhast done with a headers, cat delete pipe mid pipe and muffler section.

now when i plug the laptop into the pp6 it wont' read the afr it's stuck at 11.6 afr. you think something had happened to the o2 sensors perhaps during install? or maybe a lose clip?

what you all thinks let me know

vincent

This should probably be in engine management.

At 11.6 AFR, your O2 is probably reading 1.0V. If you were reading extremely lean, I'd say you might be disconnected.

I'm not sure about the late model Imprezas, but I know that my Legacy's front O2 sensor is a 4-wire wideband. The PP6 won't be able to interpret this signal into anything useful. The rear O2 is a narrowband, and because it's just used to check the effectiveness of the cat, it really serves no purpose for tuning. It makes for pretty flashing lights, though.

Looks like you've got some work to do with a continuity test, if it matters enough to read a narrowband O2 sensor.

PP6 is a piggyback engine management system, not an a/f meter.

sounds to me like you may need to reset the PP6 and see if that helps. i would also contact rallitek and see what they say. either that or you have a bad front o2 sensor.

i pulled the cel code that was thrown it was a p0138 which is rear o2 sensor high voltage any ideas guys why this is happening?

no idea if its related to the pp6 problemn of not since the pp6 reads from the front o2

Did you do the basic wire up that came with the unit? I had to wire in my rear o2 separately because it wasnt in the original instructions.

Did the PP6 read the O2 sensor correctly before the exhaust install?

Further, I'm surprised that you can read the front O2 at all... Maybe there's something I don't know about it?

Did you do the install yourself? The rear o2 on your car (05's) is close to the front of the stk cat section and most aftermarket exhaust moves it back about 10" down the pipe. Thats 10" of wire your stk rear o2 doenst have. Id def. check that out first. I had to extend my harness when I did my exhaust.

1. yes the pp6 worked fine before the exhaust install
2. yes th rear o2 did need wires extended and i did do that myself

maybe there was a problem when rewiring?

Apologies, but here's my take:


1. Rear O2 wiring was altered.
2. ECU claims rear O2 voltage is high.
3. AFR of 11.6 is 1.0+V

I'm willing to bet that the PP6 is wired to the rear O2 sensor signal. I can't explain why that signal would be at, or over, 1V.

How many wires are there on the front and rear O2 sensors in a 2.5RS? Is the front O2 sensor a 4-wire wideband?

problem located the two black wires were wired opposite when the o2 sensor was extended!

god damn subaru should have nicer wiring colors everything is black!