AFARR

Frozen O2 Sensor. Wouldn't move....hit it with PB Blaster, ran the engine, tried...nothing.

Hit it with PB again, go to start the engine and I hear a much too loud exhaust sound...

Right where the 2 pipes joint to the 1 pipe (right before the joint with the 'front exhaust pipe')...one has a crack of about 2 inches that is readily visible at the top.

Still have a frozen O2 Sensor.

Now I have to deal with a Manifold swap...might as well do the pipe at the same time and leave the old O2 Sensor in place...?

Possible to weld a crack like that (runs from side to side)...or is it gone?

How to prep the exhaust manifold to remove it? It's going to be weekend project at the very least....and I don't want to deal with broken studs, etc.

Thanks!

freegdr

a muffler shop can weld the old crack and install a new bung for a new sensor leave the old one there....jm2cw

AFARR

I'll probably go that way.

AFARR

CattyXJ

Go that way keeping in mind that the weld will probably crack and you'll be right back in the same position your in. I welded mine, took a month till it was leaking again. You can get a good manifold with the expansion sections in it for about $120, I got mine from carpartstoyourdoor.com. It took 3 hours to do, and it only took that long because I couldn't get the bolts between the manifold and the downpipe off. Good luck!

freegdr

this is the best way to fix it if the wallet allows or get a header and upgrade at the same time

jeepxj19

Best way to get o2 sensors off is heat, heat it up with a torch then use a o2 socket and it will unscrew fine.

CattyXJ

Agreed

AFARR

Still didn't budge.

I can handle (and did price out) the manifold (and replacement downpipe, since it has the bung installed) change...but i'm worried about breaking the studs that attach the manifold....

Any suggestions?

Thanks!

wildbill1

Again, heat. Heat the nuts until they are glowing red and they will very likely spin right off.

CattyXJ

I was worried about the bolts on the manifold too...on my '96 they surprisingly came right out. To give yourself an idea of what you're in for you can give the bolt close to the coolant temp sensor a turn to see if it moves. Like the other guys said, heat the bung, only the bung, around the O2 sensor with a torch, then turn it with a channel locks.

thakmfb

I mean obviously you were tryin to replace the sensor, so why are you worried about getting it out now that you will be replacing the manifold and downpipe? Not being a dick just curious. And the bolts on the manifold to the head shouldnt be too much of a problem on my 92 they spun right out

BostonIrish

Once you pull the intake off it shouldn't be too hard to get the bolts out.I soaked em with PB blaster and left it over night.Took me about 3 hrs total using the manual to finish the job.

AFARR

I was able to get the old sensor out today.

I soaked it in Liquid Wrench (was out of PB Blaster) overnight.

Today, I bought a propane torch and heated the bung red, did it 3 times before it finally moved. I jacked the Driver's Side up, braced my foot on the pipe (to prevent it from moving) and, with the side jacked up, was able to get a piece of pipe on the ratchet. (I have a cheater bar, but it was too tight a fit). Finally gave way.

The Manifold is gone...I checked and the pipe (rear?) where it finally joins to one pipe is cracked all the way around. So, I'm checking prices on manifolds and watching for a deal.

AFARR

Evil D

Hey guys new member, is there a straight forward write up on how to swap the exhaust manifold? Mine is cracked all the way through and i'm either going to weld it or replace it. I've asked around and i get mixed opinions on how to take one out...some people say i have to remove the intake and bring it out from the top?? Or is there enough room to come out from the bottom? Can all the bolts be reached from the top of the engine with the intake on?

Thanks.

Phragle

^ hijack