Hello,

Quick question. Got the old exhaust off in about 10 mins, however for the last 4 hours i've been screwing with the rear 02 sensor as I cant get it out. Ive gone from 3/8 impact to 1/2 and to 3/4 (nearly 800 ft lb) and I cant get it to budge....

Search the forums, most people say do not cut off the 02 sensor as its needed however there are a few who have successfully done so. If i cut it off under the body, what problems am I looking at besides a CEL if anything?

Thanks.

 

That's all...you'll only get a cel light....

 

Cool thanks for the quick reply... Cut it is.

 

if it's rusted that tight, you could invest in a new sensor too ...

 

YOu'RE going to cut the o2 sensor off the exhaust? PB blaster, WD 40?

 

+1

Soak in PB Blaster over night if you are having trouble, .

 

so your telling me that you took an IMPACT gun that has 800 fout pounds of reverse torque and it Couldnt break this thing loose? turn up the air presure to 100 psi so that you can get full power out of your gun......800 foot pounds of reverse tourque will BREAK the o2 sensor off so i don't think that your gun is in full potential......TIP only do it for 6 seconds at a time as your impact gun only has full reverse power for about 6 seconds. you can also try using HEAT as your trying to budge it with your gun.......this should work just fine unless you ahve already hacked it off.

 

PB Blaster will do the trick. PB Blast it every 10 minutes for an hour, then hit it with that impact and youll see it come flying off. Guarenteed.

 

oh damn..

rear o2 sensor is about $250 brand new..

if the secondary o2 sensor missing or malfunctioning, it will cause the ECU switches to LIMP mode.. you can drive the car, but the car won't perform well..

 

you will need three things....22mm wrench (with closed end....sensor harness will fit....trust me), hammer, & PB blaster.....Spray the PB Blaster and let it sit for 30-45mins (Apply a few sprays) then grab the sensor with a 22mm wrench and grab the hammer....go to town with the hammer on the wrench...worked for me on several cars....the rear & front o2 is a PITA....

 

Had the same problem last night with the bolts attached from the rear of the cat to the cat back. I couldn't get, a friend who is a mechanic couldn't get, and finally it laughed at the impact!

Good luck, but like they said, PB Blaster.

 

wait o2 is not 250! lol

 

Dont do things the redneck way on your EVO by cutting it off. You may need it later.

 

Unscrewing that rear o2 should have been the first thing you did when your exhaust was still securely bolted to your car. I know, hindsight. . . .

 

I had the same problem, tried unscrewing it while under the car, no luck, finally unpluged it from the harness, drop the exhaust and got it that why, although it was a bi*** to take out... ended up stripping the threads on the o2 sensor. Not running a rear o2 right now, no limp mode though... will just get a simulator this weekend...