Removing O2 sensors

[Robot_trainer]

So Im up to my ears in this header install. The manifold nut removal has been interesting. Im using a quickjac so the car is at a comfortable height but still on my back. Im about to remove the h pipe. Looking at the O2 sensors, im feeling stupid that I cant figure out how they unplug especially the fronts or where the wiring is clipped. I cant see up there. Anyone have any tips while I take a break and decompress?

 

[RBB]

So Im up to my ears in this header install. The manifold nut removal has been interesting. Im using a quickjac so the car is at a comfortable height but still on my back. Im about to remove the h pipe. Looking at the O2 sensors, im feeling stupid that I cant figure out how they unplug especially the fronts or where the wiring is clipped. I cant see up there. Anyone have any tips while I take a break and decompress?

They’re a bitch to get to. They plug in up on the top side of the transmission. Since you’re installing long tubes and you’ll need to unclip the wiring harness from the transmission anyways (you don’t want to use extensions), you might as well start doing that and the plugs will then be easily accessible.

 

[Robot_trainer]

I got it. What a bitch. You would believe me if I told you how I got it unplugged. It involved a flexible grab claw and a screw driver. Had to look at the extensions and a new O2 sensor I have to figure out how to unlock it. Unclipping the harness fron the trans doesnt seem to free much length up. Maybe a couple of inches. Is that all it need to ditch the extensions?

 

[Robot_trainer]

Got the passenger side plug to reach as far as where the o2 sensor screws into the exhaust pipe. Should be ok

 

[merkyworks]

Just an FYI.......
Don't use extender harnesses for the front O2's, this typically causes issues. The factory harness is long enough if you unclip it from the trans and body as RBB mentioned.

 

[Robot_trainer]

Thats what I keep reading, however Im stumped. I thought I had it but one I removed the h pipe it looks like neither will reach. Ive unclipped it from the right side bell, middle and left. All thats left is the clip on the drivers side trans. The harness appears to be 1 piece so if I pull it it one way it will be short the other. Am I missing something? Is it just a matter of unclipping it and the pigtails on the o2 just reach? The headers arent in yet so maybe its the routing of the pig tails?

 

[merkyworks]

Wish I could give more details on what to do but I had a shop install my LT's. I just know with the trans in they unclipped the harness from the body/trans mounts and ran it such that no extension harness was needed.

 

[Robot_trainer]

Well all I can do is unclip it all along the trans and see where everything ends up

 

[Imatk]

I tried replacing my 02 sensors once.... I admire you sir for doing it. I wound up burning the crap out of my arm on a cat because I'm a moron... then after waiting for everything to cool I could never get hold of the damn things.

I gave up so kudos to you for getting this far!

 

[Robot_trainer]

I tried replacing my 02 sensors once.... I admire you sir for doing it. I wound up burning the crap out of my arm on a cat because I'm a moron... then after waiting for everything to cool I could never get hold of the damn things.

I gave up so kudos to you for getting this far!

 

[Robot_trainer]

Well my deremination goes up when these so called specialty shop either try to rip you off or they dont call you back because you are not spending 40k. So I decided to spend the money on a quickjack and extra tools and if it takes me all winter so be it (removing the last manifold tomorrow, one week in). I wont lie, its been an epic battle but Im learning more about my car. I think Im doing the right thing with the sensors. They are all on the same harness. You pull one side and the other goes short. Im sure there is a balance.

 

[RBB]

Well my deremination goes up when these so called specialty shop either try to rip you off or they dont call you back because you are not spending 40k. So I decided to spend the money on a quickjack and extra tools and if it takes me all winter so be it (removing the last manifold tomorrow, one week in). I wont lie, its been an epic battle but Im learning more about my car. I think Im doing the right thing with the sensors. They are all on the same harness. You pull one side and the other goes short. Im sure there is a balance.

Somebody posted a nice diagram of how the harness clipped into the trans at one point, but I can't find the thread for the life of me. Here's the best I can do....take a look at this picture and zoom in. The harness is clipped into and goes above the bell housing. You need to remove the drivers side transmission connectors, the drivers side O2 connector, pull the 3 tabs on top of the bell housing and then you can pull the harness to the passenger side. You can reroute it however you want once you get that done.

 

[Imatk]

Well my deremination goes up when these so called specialty shop either try to rip you off or they dont call you back because you are not spending 40k. So I decided to spend the money on a quickjack and extra tools and if it takes me all winter so be it (removing the last manifold tomorrow, one week in). I wont lie, its been an epic battle but Im learning more about my car. I think Im doing the right thing with the sensors. They are all on the same harness. You pull one side and the other goes short. Im sure there is a balance.

Absolutely man I understand. Yeah the harness will only plug in one way. That's to prevent the accidental swapping from driver's to passenger's.

 

[Catmonkey]

I ran the harness end that goes to the driver's side under the transmission. The wires will be too short if it goes over the transmission. I'll try to get a couple of pics this weekend.

 

[ILW84U]

Here are some instructions I copied 7 kept for future use.

O2 sensor no extension



Disconnect the front and rear O2 sensors from the exhaust.

Trace the wiring harness down from the passenger side and it will attach to the bell housing and transmission on the driver side.

Remove all push pins and attachment points and flop the wiring harness from the driver side to the passenger side.

Pull the wiring harness from below with just a little force to remove slack in the harness.

Re-install all O2's with no extensions.

 

[Robot_trainer]

Somebody posted a nice diagram of how the harness clipped into the trans at one point, but I can't find the thread for the life of me. Here's the best I can do....take a look at this picture and zoom in. The harness is clipped into and goes above the bell housing. You need to remove the drivers side transmission connectors, the drivers side O2 connector, pull the 3 tabs on top of the bell housing and then you can pull the harness to the passenger side. You can reroute it however you want once you get that done.

View attachment 1527656

Thanks man! Thats a great help! Needed to see the egr tube routing too

 

[Robot_trainer]

Thanks! Thats awesome! I figured it out but the pick also shows the egr tube routing. Unfortunetly Ive hit a wall. Got the passenger side header in but cant get the drivers side in. Ive hit my limit. Going to trailer it to a shop to get it finished off.

 

[Imatk]

Damn man, sorry to hear that. But I give you all the credit for giving it a shot!