Question about 02 sensor

T-Bone · Post by **T-Bone** » Fri Dec 02, 2005 4:20 pm

I was wondering what would be the easy way to get to the 02 sensor? I just bought my tercel last weekend and the 02 snesor bolts were both broken off. From what it looks like I will have to drill the bolts out and tap new threads in the holes. It seems like it would be kind of hard to get to from the top of the engine bay.

Post by **ARCHINSTL** » Fri Dec 02, 2005 6:20 pm

A long shot, I know, but do enough of the studs protrude so that a stud remover can be used? The only remover I've ever seen (or used) is a Craftsman, bought about 40 years ago. I doubt the one I have could work, as it was intended for longer studs, like those used in a block to mount a head, but more specific ones may exist. Another really long shot would be to use PB Blaster on the studs and drill and try to use an EZ-out extractor - but don't break off the extractor in the stud - I can vouch for the difficulty in attempting to remove a broken extractor..... Heat on the manifold probably would help in these removal maneuvers.

If you have to drill and tap, your best (and probably only) bet for accuracy in tapping is, unfortunately, to remove the manifold and go from there. A tip I learned in removing the manifold's two inner nuts is to use a 6-point socket instead of a 12-point, as it is just enough smaller in diameter to fit in between the manifolds (at least with Craftsman sockets). I also had to use a flex fitting on the right nut. There is a thread about this (3AC manifold) in Repair Questions, as well as one about the exhaust pipe bracket, which would also be good to check.

At which point, you might as well pop for a manifold gasket and the 3 carb mounting gaskets (a new O2 sensor gasket usually comes with the sensor) - and use anti-seize on the bolts.

Good luck, and keep us advised on your successful procedure of choice, as one never knows for whom next the bell will toll...
Tom M.

takza · Post by **takza** » Sat Dec 03, 2005 5:34 am

You need to look at it from below...if some stud is protruding...I'd soak the hey out of them for a week with PBBlaster or ???...and try large vise grips...not easy to work under there.

Possible to use the heat of the exhaust AND PBBlaster???

Post by **ARCHINSTL** » Sat Dec 03, 2005 12:48 pm

I second takza's advice - one thing I've added to the procedure for rusted fasteners (which everyone probably does already) is to take my faux Dremel tool's wire brush to the juncture of the bolt and the surface of the item and remove as much rust in that crevice as possible. It looks like it would help, and belief in the Force is paramount in working on our little cars.
Tom M.

T-Bone · Post by **T-Bone** » Sun Dec 04, 2005 8:41 am

thanks for the help. i got in there for a closer look and the bolts are flush with the flange where the sensor mounts. for now i made a mounting bracket to hold the sensor into place. i came to the conclusion that once it gets warmer out i am going to just remove the manifold, put it in a vice and drill out the holes and tap new threads (we just got a lot of snow is its getting very cold out). I am also going to get a rebuild kit for the carb and rebuild it when i have it all out.