Exhaust leak around my O2 sensor

[1fastII]

I put a Stinger 3" downpipe on my SVO. I put a new O2 sensor on the car, but I have a leak around it now. I've tightened the hell out of it, even when hot. I also tried putting another copper washer on there in addition to the ones that came on it out of the box, but that just made it worse. Any ideas?

[svobud]

teflon tape maybe? That or try another O2 sensor. If it still leaks - you might consider the threads on the DP you bought to be FUBAR'ed.

[1fastII]

Wouldn't the heat from the exhaust disintegrate teflon tape? I'll give it a try, but it wouldn't surprise me if the threads were messed up. The section of the downpipe with the O2 sensor bung is a used stock downpipe. It screws in easily, though.

[Pat_in_L.A.]

Originally posted by 1fastII
The section of the downpipe with the O2 sensor bung is a used stock downpipe. It screws in easily, though.

Do you mean "used stock downpipe", or do you mean "used cast iron elbow"? Teflon tape is not likely going to be a permanent fix. If cast iron, someone may have previously overtightened the threads and done permanent damage. If it's a nut welded to the downpipe, the nut can be ground off and a new 18mm nut welded on in the same place.

PLEASE NOTE: The O2 sensor CAN NOT BE INSTALLED PARALLEL WITH THE GROUND! It needs to be installed with at least a 15* downward slope, otherwise humidity will collect inside it in critical areas that will destroy it prematurely.

[Erics SVO]

Did you apply never seize? I had one "stop" on me and it was because I didn't use never seize, was galled about half way. Applied never seize and it went all the way!



HTH, Eric

[1fastII]

Yeah, I meant used stock elbow. I'll try some anti-seize.