O2 sensor rusted bolts

So went to change my o2 sensor because I got the code for it and my truck is starting to give the signs . A little hesitation when driving . Air flow doesn’t feel right . Anyway . I went thru the steps on un plugging the sensor under the passenger seat . With my luck it’s attached to 2 studs with bolts at the end . But as you’ll see it’s completely rusted . I have no idea what to do . I seen previous forums on o2 sensor and using a craftsman lock out kit and getting it out but I don’t have nothing really to grab on to . This old rusty son of a b has caused me so many issues lol.

 

Hear some better angles of it . Tried to put a video but that didn’t work . Thinking maybe a torch ?

 

This is the downstream o2 sensor on a 01 Toyota Tacoma non 4x4

 

Perhaps this:

ARES 70016 - Damaged Bolt and Stud Extractor Tool - Grips and Removes 1/4" to 1/2" Studs - Ideal for Broken, Rounded Off, Painted Over, and Rusted Tight Bolts

https://www.amazon.com/gp/product/B01GKEBG9I/

I used it to remove a sensor bolt that had snapped in half.

Could also try heat. Torch it... with care of course.

Can also find extractors at the local hardware or auto parts stores.

Granted I had more threads showing on the snapped stud I was dealing with, this is what it looked like. The extractor made short work of it. Came out clean. Of course I was dealing with quite a bit less rust than you have.

 

Looks like the nuts are gone already? Just pry off the sensor along with the flange. New sensor comes with a new hold-down flange.

https://www.tacomaworld.com/threads...t-bank-1-5vz-fe-w-manual-transmission.448490/

 

Replace the mid-pipe.....from the cat backward.

https://www.oreillyauto.com/detail/.../v/a/8217/automotive-truck-1997-toyota-tacoma

 

It looks to me like those studs are welded/brazed in there....

It might be easier to try just to screw the sensor out.....

does the new one screw out of that plate??

.....messing with any of that could crumble away......

Or are you faced with replacing that back half of exhaust anyway in next few years.

 

OP those studs normally have nuts holding the O2 flange on, yours are totally gone and the stud is disintegrating.

Tricky call and may require more fab abilities than you have available to you, but I would probably try to just pry the O2 sensor/flange off. Then I'd probably try to use vice grips or something to rotate the studs out of the exhaust and install new studs if possible. If they don't want to come out then you may have to get creative with heat and/or weld to bust them loose. Possibly re-tap the hole or something.

Rust!

 

50/50 mix of ATF and acetone. Let it soak

 

Heres everything you need to know:

https://www.tacomaworld.com/threads/old-oxygen-sensor-removal.736791/#post-26228869

I went through the same thing and tried lots of things (soaking in pb blaster, heating them up, cursing at them) but the nuts were completely rusted round and merged with the studs. In the end I bought a small file and filed two sides of the nut flat so I could get a wrench around them (see attached image). They came right off.

Most of your nuts are gone so all you have to do file down one side till you hit the stud and then pry/knock them off with a flathead screw driver. Note that you can buy new studs if you break them... but they are gonna be hard to get out.

 

So are u saying knock the studs off. And replace em?

 

I'd replace the midpipe. I suspect that's what's going to happen anyway. I doubt you'd ever get new nuts to torque down on those studs.

 

You know the studs are threaded into the bung, and can be replaced right? Cutting the pipe out and replacing it is a bit excessive, especially since this scenario was specifically taken into consideration in the design of these parts.

 

Did you try to unscrew the O2 sensor from the flange ? Did it not come out and that's why you are trying to remove the flange?

 

Didn't know that, I'll still be surprised if they come out w/o snapping off but anything is possible.

 

I wouldn't "knock the studs off" unless you have to, but I wouldn't be shy of filing (or grinding if you have a dremmel or die grinder) the threads closest to the o2 sensor flange.

I would start by heating cycling the studs a bit while taping on them. Not so heavily as to bend them, so maybe straight down them if possible. Heat + impact should free them up. Then get a screw driver or pry bar between the o2 sensor flange and bung. It really shouldn't take much.

Once you have the sensor out, the two studs are threaded into the bung. PB Blaster (or 1 part acetone + 1 part ATF), let it sit, tap the studs again, heat the bung (not the stud) and try to remove the studs. File flat spots onto the studs so you can get vise grip on them.

 

Of you can try wire brushing what remains of the studs and weld on a new nut. That combines with heating of the studs closest to the actual exhaust pipe might do it.

 

Dont knock the studs off . File down the nut so one side is open and free. Then you can pry/knock the nut off. Here is a bad example but illustrates the concept. This guy went too far using a grinder but you get the idea.

 

A muffler shop usually uses oxygen and acetylene to heat it up before removing it. I've tried using MAP gas before and it's still not hot enough.