clapper

Hey guys,

The wires on my rear o2 sensor came out so i bought a replacement. I went to take the old one out with and o2 sensor wrench and it ended up rounding itself off. I've tried to get it off with no luck. How important is the rear sensor on theses vehicles? Will i loose performance or mpgs by not having it plugged in? The car feels normal but right after the cel came on i did notice the idle was rough, it has since smoothed out.

Thanks!

Mike

FL Denmark

the rear o2 sensor is there only to monitor the efficience of the cat. however, some ecu's dosent like any present errors and goes into a mode where it sets inputs to a preset value. so that way you can loose mpg.
but a new sensor is 50$ and if you drive the car really hot, you should be able to get it out.

good luck

clapper

I actually tried torching it too and still had no luck, the biggest problem is that it's rounded off so i have no way to get a hold of it. Minnesota winters have really taken a toll underneath this thing.

Mike

DFlintstone

Sounds like a booger. You know heat makes metal expand. You want the sensor cold and the rest hot. Liquid Wrench or PB Blaster will help. Will a pipe wrench reach......

jeepxj19

Are u using a o2 socket? Heat it up real good heat were it threads into the pipe. Worst case cut the pipe out weld in a new one and by a new sensor try not to get a bosch some jeeps don't like em.

clapper

Yeah i used an o2 socket, i've also tried a torch. At this point i think i'm just going to leave it, i'll try a pipe wrench tomorrow though.

wjnfirearms

Part of the issue could be just how hot did you make the pipe. If you used a blue bottle propane torch, it possibly didn't make the pipe hot enough. I use a MAPP gas torch (yellow bottle). It's the next best thing to oxy, which I do have also. Soak the threading in a good penetrating oil for at least several hours and then make sure the pipe is really hot and get something around the sensor like a large set of Vice Grips. Truthfully, I never heard of a sensor socket rounding a sensor out, so this one is a new one for me. Using wrenches, yes. Never a sensor socket. The sensor must have been pretty deteriorated for that to happen. I did have one on my V-8 truck actually rip a piece of the pipe the sensor was mounted in out of the manifold pipe. I had to put the piece in a vice and heat the heck out of it to remove the sensor. It turned out to be cross threaded by whomever installed it by the previous owner. I welded it back together and installed the new sensor.