[OOPS] So I’m finally replacing both downstream O2 sensors and this happens (1 Viewer)

[zcostilla]

The post was tight but didn’t feel cross threaded. Then it got just a little tighter and then snapped right off. Is there a simple fix? Or am I screwed?

And also, my new sensor came with a spacer that has seals on both sides, but there weren’t any on the old sensors. Do I use them or toss them?

 

[Trunk Monkey]

There's enough threads on there to get some pliers or vice grips on. Hit it with oil for a bit, maybe heat too.

 

[zcostilla]

There's enough threads on there to get some pliers or vice grips on. Hit it with oil for a bit, maybe heat too.

I’m not sure we’re on the same page here. That’s the end of the post, stuck in the nut, in my socket. It snapped right off. The other side came off fine. Just worried about making this work with only one side tightened down.

 

[Trunk Monkey]

the "post" is just a threaded stud

 

[FxFormat]

Remove the gasket, if there's a lot of thread left, screw one nut on, then the 2nd nut, then use a wrench to loosen the bottom nut, the top nut won't move and it'll just spin the whole stud out.

 

[zcostilla]

the "post" is just a threaded stud

View attachment 3104566

Remove the gasket, if there's a lot of thread left, screw one nut on, then the 2nd nut, then use a wrench to loosen the bottom nut, the top nut won't move and it'll just spin the whole stud out.

So any idea what the threads are on that stud, so I know what I need to buy?

 

[FxFormat]

So any idea what the threads are on that stud, so I know what I need to buy?

Probably M8 x 1.25, bring the old nut with you to advance auto part and match it up, but likely it's the one i mentioned. For installation, you dont even need a stud, just get the same size bolt that's not too long and secure it, as long as it's tight and doesn't leak you're good.

 

[Fj80oregon]

Take the nut on the good side with you to the hardware store and compare. Almost all the thread pitch on 80 series is 1.25 I’m guessing m12x1.25

 

[Fj80oregon]

Or m10x1.25

 

[bigredmachine]

12mm nuts and bolts are 8x1.25 thread. and im guessing that the spacer that your talking about is the gasket, yes youll want to install that when you replace the o2 sensor

 

[e9999]

pretty much any decent hardware store will have some sort of system to measure threads for folks to use. Of course, if you plan to do some DIY you might want to buy a set of thread gauges, I use mine frequently.

I would suggest care when removing it if it appears stuck. You still have some thread to work with, which is great, but if you break it flush it will be much harder. So I would really work on that stud before trying to remove it for real, with several rounds of alternating good penetrating oil and heat before anything else. You could also shock the stud by hammering on the end (after putting on the nuts). I should add -but consider at your own risk- that in the past I have had very good luck tightening a smidge a stuck rusted bolt before loosening it, counterintuitively enough.

 

[GTV]

Heat is your best friend, can't stress that enough.

 

[e9999]

^ yes, in general, but this is exhaust so it is already heat cycling all the time unlike the usual situation, so heating things may be less dramatically effective than usual.

 

[GTV]

^ yes, in general, but this is exhaust so it is already heat cycling all the time unlike the usual situation, so heating things may be less dramatically effective than usual.

Heating with a torch and expanding the interface is a different thing than normal heat cycles.