bolts? on the outlet of drivers side cat (anyone changed out the driver side cat). | Ford Explorer Forums - Serious Explorations

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bolts? on the outlet of drivers side cat (anyone changed out the driver side cat).

sehaare

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Joined
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City, State
Chicagoland, IL
Year, Model & Trim Level
98XLT 4WD SOHC,94XLT gone
SOHC

Ok, so even though I had soaked it overnight with kroil, the front passenger side (right) O2 sensor stripped out the bung when it broke loose.

So now I'm trying to drop the passenger side exhaust to try and tap the bung and to replace the other two O2 sensors in the sections of pipe connected to it. That section of exhaust piping is also connected to the section of piping that connects to the outlet of the drivers side Catalytic convert. So I need break the connection to the driver's side converter as well(everyone confused now?).

Everything was going relatively good until I got to that outlet flange on the driverside cat. The fasteners are so rusted I can't tell how they come apart. It looks like the head of the bolt has been welded to the flange. but on the other end I can't see any threads.

Has anyone broken this flange before? What type of fasteners are they? Did you have to grind out the old bolts? I'm not sure that I have room enough to grind them?

exhaust_zpsukutxsl7.jpg
 






Don't try to take that joint apart. Take it apart at the flange above the cat on both sides and take the whole Y down. A cutting torch and/or a cutoff wheel is the only way that middle joint is coming apart.

How badly is the bung stripped? If it isn't bad, you could try running an O2 thread chaser in there in place. But if the threads are ripped out, you're going to need some sort of insert.

Heat those other sensors with a torch before trying to remove them.
 






Don't try to take that joint apart. Take it apart at the flange above the cat on both sides and take the whole Y down. A cutting torch and/or a cutoff wheel is the only way that middle joint is coming apart.

How badly is the bung stripped? If it isn't bad, you could try running an O2 thread chaser in there in place. But if the threads are ripped out, you're going to need some sort of insert.

Heat those other sensors with a torch before trying to remove them.

Thanks for the heads up to keep me from making a big mistake.

The flange above the passenger side cat came apart easily since it had been take apart recently by a shop for something else.

Is there any concern about the threads stripping in the manifold that the driver side cat flange bolts to?

I think that I'm starting to get in over my head here fast and don't want to have a stripped out manifold.

I tried a O2 thread chaser on the stripped out bung but couldn't get it in straight with the pipe still on the car. So I'm trying to drop it to get a good angle on it to try re-threading it. And while it is off it will be a lot easier to get at the last two O2 sensors.
 






There's always a chance of stripping them, but I don't think that is a big risk. More likely you would have it snap off. I didn't have any trouble getting mine apart. All the usual rules for rust apply here. If you can get to it, wire brush as much rust off the threads as possible. Soak with PB or Kroil ahead of time (if you have 'ahead of time'). If they don't come apart relatively easily, heating with a torch will do more to help than anything else. If it breaks off, you can either drill it out and put in a new stud, or bolt all the way through with a nut on the other side. Lots of people have done that. But I think you should be able to get it apart. As I recall, the driver side is the easy one anyway. Use impact if you have it.
 






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