yeah...I just installed my new GReddy Cat back system and had a hell of a time getting the O2 sensor out. I did everything, used all sorts of lube, turned the car on for a while to get it hot and tried it, turned the car off and let it cool down and then tried it. It just wouldn't budge. Finally I pulled the pipes completely out and stood on the wrench and it came out, but unfortunately I beat the sensor up pretty bad. Now I got a MIL lamp on in the car. I ran a diagnostic on the ECU? and, as I thought, I found out the O2 sensor is responding slowly (0707). I don't have enough money right now to buy a new one, is it still cool to drive around? I don't even know how much the sensor does for the car. aren't they like $170.00?
mitch

 

The ECM doesn't use the rear O2 sensor for adj fuel/timing...

You may have shorted out a wire... was there any exposed wires?
The GReddy kit has the O2 Bung positioned where it is too close to the heat shield... I shorted my heater circuit and popped the 15A fuse... I had to take a hammer to the heatshield and patch the wires. My MIL code was different, though

 

yeah, one wire was exposed but I re-insulated it and capped the connections. Would the diagnostic show a slow O2 sensor or a completely dead one? Anyway, what your saying is it shouldn't cause any problems, right? just annoying to see that light on.

 

yeah, you can run with it...

But if you had repaired the wiring.. the problem should go away after you reset the MIL... Did you already do that?

 

yeah, the MIL is still on

 

Then if the MIL still indicates rear O2... you'll need to replace it later.

 

If you want to go cheap you can get a universal three wire O2 sensor and wire it to the stock connector yourself. It's the rear O2 sensor, which isn't used to control emissions anyways, so no sense spending $$ for Nissan parts.