So I am replacing a Pre-Cat O2 sensor and after much time and bleading knuckles I got the old one out. When I pulled it out I already feared the worst the threads on it looked like someone took a hammer to them. I am ATTEMPTING to put the new one in and so far have achieved nothing but pissin off the wife with my cursing. The threads inside the cat are still there I can feel them but if Im correct one part is messed up causeing the sensor to slip right out once its barely started. Any ideas on what I could do to A. fix the treads or B. make it work. At the very least I need to be able to drive it. Ive looked into tap and die sets but dont think that any of the taps will be big enough to rethread that size hole. Oh how I love it when simple projects turn into crap.

 

can you use the old O2 sensor as a tap to clean the threads. use some oil or wd40.

also, i'm not sure but a spark plug MIGHT be the same threads.

edit - if you need to you could drive it w/o an O2 sensor. it'll set a code, be loud, and stay in open loop, but it should run ok.

 

I doubt I could use the old O2 for anything but a light paperweight now theres no thread left on it at all. Ive triedm bearing grease cause its the only thing i had handy and no dice. Do you think actual oil will make a difference?

 

Check the thread count against an old spark plug. If its the same most auto parts stores sell a chaser for a spark plug. Mine is double ended and it only cost a few bucks. Plan B would be to take the new O2 down to a nut and bolt shop and have them match the thread count. Bad part about that plan is the price of a really big tap.

 

what about heating it up with a torch? not the o2 but the cat. its how i got out the old one well that and beating it lol. Ive been calling around lookin for a tap big enough and so far no dice all the mechanics are closed today. i dont know im starting to think duct tape.

 

O2 sensor gertie. Don't think the threads are the same size as a spark plug. That would be just way to convenient, and the engineers would never let that happen......

 

find a bolt at lowe's? and if i did that, i think id try heatin it up a bit and then run the bolt down and back out a couple times.

 

If you can find a bolt with the same thread you might try cutting a slot lengthwise at the end of it and use it as a thread chaser.

 

Just drove it to a muffler shop and have them weld a plug to that bung and weld in a new bung for you, shouldn't cost but $50 if that.

 

hmmm those sound like dynamite ideas time to start callin around again see whos open. thanks