Damaged nut on O2 sensor

Finally broke down and purchased a new upstream Air/fuel sensor (sometimes referred to as an O2 sensor ) Put Kroil penetrating oil on the studs the night before and went to take it off this morning.
One of the well rusted nuts rounded off and of course it was the one that was the hardest to reach. I couldn't grab it with visegrips or drive a splined socket on it.
I was able to use a cut-off wheel on a Dremil tool to cut a notch in the nut. I then used a screwdriver and a hammer to rotate the nut just enough to break it free. I was able to force a 6 point socket on it and get it all the way off.

Thought I'd share that technique.

Anyhow, new Denso sensor in place, no more Check Engine Light, truck runs better - All is well

 

I'm dreading ever having to do this job for the same reason. The nuts on mine are just round. Maybe if I'm lucky they'll just disintegrate and fall off like they did on my 4Runner!

 

Not much room up there. it wouldn't be that tough if there was just a bit of clearance. The Dremil tool really did the trick!

 

damn that sounds like a 30 minute project that turned into a few hours project. lol. i just ordered 2x new o2 sensors. hopefully my install goes a little more smoothly.

 

It was more like a 45 minute project but I got lucky when I was able to break it free!

Well 50 minutes if you count the beer.

I'd rather be lucky than good any day of the week !

 

maybe this will help.
http://www.tacomaworld.com/forum/1st-gen-tacomas/142451-rear-o2-sensor-done.html

 

I broke the upper stud off (accidentally) and just used a hose clamp to hold that side of the O2 sensor on. It works and I'm not worried about it, it should last until I can afford a new header.

 

^My upper stud broke as well but I just modified an exhaust u-bolt to hold that side of the O2 down.

 

I did my upstream today. Some how managed to thread the bolt out when the lower nut hung up. Couldn't believe I didn't snap it!! Was able to thread it back in and got the nut tightened back up. The downstream will be a different story. I can feel the nuts are rusted to shit! Can't see because the heat shield. CEL is off and running better than ever. Thanks to TW for helping w the ridiculous location of the plug over the tranny!!! Would have never thought to go in thru the gear shift.