Topic: Oxygen Sensor Rattling

[Weldo]

OK, so I notice my O₂ sensor is rattling, no big deal, But it seems the nuts that hold it down are gone.  My sensor mounts right in front of the catalyitic converter.  I can't see the mounting nuts, but it feels like htere's no nuts at all    on the studs.  It kinda felt like E-clips, but they were probably washers, I couldn't imagine they'd use clips instead of nuts.  So could anyone tell me the thread size and pitch so I can get replacement nuts?  (Hope the studs aren't too far gone!)

[scheid6996]

WELD IT

[Ferg]

WELD IT

NO DON'T

[scheid6996]

 

[mr4x42u]

That pretty typical,,rust and heat rape it..A small tack may not hurt..I guess it depens what o2 sensor were talking about and on what year rig,,they differ in design..i think the tacoma ones cam be tacked if thats what it takes..I think I would just replace the pipe and sensor and just bite the bullet..

[Weldo [OP]]

Its a 91, pickup, 22re.  Any chance I could just replace the nuts?  I don't see why not as long as the threads are still somewhat intact.  Anyone know what size and thread pitch the nuts might be?  Any close estimates even?

[BLACKDOG]

they're 12mm nuts I beleive, possibly 10mm.  (its been a few weeks since i took mine off)  and i dunno about the pitch   get some silly putty, or bubble gum, and press it to one side of one of the studs.  Then take it to the hardware store and match the thread iprint with the right bolt, then find the nut fr that bolt.  My grandpa used to do that all the time.  He used silly putty because he could make the mold, then put it in the little egg, and not have to worry about the imprint gettin messed up  goodluck

[Weldo [OP]]

Wow, thats genius!  What a great idea!  I'll give that a shot, thanks!

[Weldo [OP]]

I did the putty thing, only with a wad of stick tack, it worked great.  Found the thread pitch to be 1.25.  I got some 10mm washers but they were too big.  The nuts ended up being 8mm x 1.25.  Thanks for all your help, everyone!

[Uncle Jesse]

10 mm is going to be what size wrench fits on the nut, not the size of the stud itself.  Clean the area around the sensor and check back in a while, see if there is any black soot around it.  If it was rattling it may have burned out the gasket a bit.  Then on the other hand, I think the stock gaskets have a fire ring, so maybe you'll be ok

[Uncle Jesse]

By the way, a lot of bolts and nuts on toyotas are 1.25 pitch, so keep that in mind.  Some places call that a fine thread metric.

[BLACKDOG]

I did the putty thing, only with a wad of stick tack, it worked great.  Found the thread pitch to be 1.25.  I got some 10mm washers but they were too big.  The nuts ended up being 8mm x 1.25.  Thanks for all your help, everyone!

glad you got it done My grandpa used to have those silly putty eggs in his toolboes, and no one could figure out why he had them   I think it is a great little trick.  Glad it worked

 

[Weldo [OP]]

I got another problem.  Got the nuts and ran 'em on, tightened 'em up, but the sensor is still loose and rattling.  I cranked those nuts down pretty good, but the sensor didn't tighten down at all.  Maybe the gasket is gone and wont allow the flange to tighten up all the way?  I still have a suspicion, though, that there's E clips on the studs because even though the nuts were gone off the studs, the sensor wasn't coming off, it just lifted about 1/8" or so.  Maybe the washers are just rusted tight?  I wish I could see up there but there's not much room to look around.

[BLACKDOG]

I dont have any clips on mine, its just the two nuts.  check the gasket.  I'll go out and look at mine, but it is a 3.0 so i dunno if it will be different


Edit: I just went and looked, its just the two nuts, but there is a heat sheild that slides over the studs as well.  If you are missing that, that may be why it doent tighten down all the way.  Is your O2 sensor itself loose in the brakcet that is held down by the two nuts? 

[Weldo [OP]]

I found the problem!  What it was, was the nuts that were on there had rusted down to little rusty sleeves like, rusted in place on the studs.  When I went to tighten the new nuts, the new nuts tightened up to the rusty sleeves and not to the base of the oxygen sensor.  All I had to do was throw on 2 washers per stud to space the nut above the little rusty remnants of the old nuts.  Problem solved.  I didn't even notice my gasket, maybe it was rusted in place and stuck, but I just tightened it down real good.  Oughtta be good til I replace the exhaust with something better.  Thanks again for all the help!