Cross Threaded Exhaust Manifold & O2 Sensor

[John]

It appears that the O2 sensor pops out of the exhaust manifold when accelerating hard on my son’s Jeep Grand Cherokee. When I got under the Jeep, I found out the previous owner cross-threaded the O2 sensor into the manifold (the O2 sensor threads are fine, it’s the manifold with the problem).

Any ideas on how to get the sensor to stay in the manifold? Right now, I was able to get it to stay in place, unless you accelerate hard, then it pops out. someone mentioned Loctite, but that only hold up to 600F, which I believe isn’t high enough. Thanks in advance.

Topic

[none]

There are aftermarket options for replacement O2 sensor bungs. If you’ve got a welder available, you can definitely weld another into the pipe.

[Nick]

Unless you can weld, I would just replace the exhaust manifold, by the time you pay a welder you will be in it for about as much as a new manifold anyways. Especially if you are willing to use salvage parts.

[none]

Feel free to disregard what I suggested earlier. I completely ignored the word manifold in the original post. +1 for salvage yard manifold replacement. car-part.com should help you find one at a nearby salvage yard. I just looked at local dealer prices vs salvage yard prices for my area. The dealer sells theirs for about $170 while the salvage yards bounce between $20 to $65 for a used exhaust manifold. You’d probably want to have new studs and nuts handy along with a new gasket. I have seen a couple of the 4.7 manifolds with broken studs in the heads.

[college man]

If its easy to get to you may be able to put a helicoil in.

[Author]

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