[GTRZilla]

Hey I guess. So after I installed my downpipes I put the rear O2 sensors the wrong way around and now I get bad idle and CEL every day since I clear it with MHD.
I can't really swap them there, I have to remove one downpipe to do so since the O2 bung is on a weird angle.
Where do I swap it in the engine and how do I know which is which, so I don't swap the front ones

[Boland01]

Just switch the connectors where they connect on top of the manifold. That's assuming you have enough wire length to do it.

[Faredo]

Originally Posted by Boland01

Just switch the connectors where they connect on top of the manifold. That's assuming you have enough wire length to do it.

he said rear not front.

[IllSic_Design]

I believe the front turbo sensors have black cable sheath and the rear turbo sensors have grey cable sheath. I know they are both color coded though, so look how you have your precat o2 sensors setup(which color sensor is on which turbo) and the sheath colors should match that at the postcat o2 sensors.

[Boland01]

OK on the rear just drop your splash guard and switch the connectors that are under the transmission-back of the engine.

[RocketSurgeon]

If you disconnect one of the sensors then read the resulting codes, you can figure out which plug is which.

[GTRZilla]

Originally Posted by Boland01

OK on the rear just drop your splash guard and switch the connectors that are under the transmission-back of the engine.

Both plugs are different, you can't switch them. Only way is to switch them where they plug in the engine. That was the first thing I tried when the CEO came on

[raptorman5174]

Originally Posted by GTRZilla

Both plugs are different, you can't switch them. Only way is to switch them where they plug in the engine. That was the first thing I tried when the CEO came on

This is correct, I am having a similar issue. I have Ar catless DP's and have this error code about the POST O2 sensor connection reversed. So today after work I jacked up the car and crawled my ass under there and YUP. You can't switch them they are keyed differently. It's almost like they are in the wrong DP's

Would replacing both POST CaT O2 sensors with new resolve this issue?

[cruizinmax]

A full downpipe install takes me about 3-4 hours on a RWD car. Taking 1 downpipe off to switch the sensors doesn't really take that long. I had to do it on my first dp install many years ago. Don't switch the sensor plugs around. Your just asking for problems in the future for yourself or the next owner. Please fix it properly.

[BMDoublYou]

Use a small screwdriver to pull the individual cables from plug a, and insert them into plug b, and vice versa. Presto. This is what I did and worked flawlessly