Is it 18x1.5?...Just wanted to make sure before I get a new bung welded for a pipe.

(Of course, this is for a '99 whereas the o2 sensor is NOT in the catalytic converter.)

I searched and couldn't find a straight answer. Maybe a call to Dallas would be my best bet.

 

i think you are correct.

 

Ditto that...M18x1.5 is the correct bolt size.

 

Thanks John!

 

Happy to help Bro!

 

The O2 sensore IS in the cat on my 99.....

 

Very strange...take a look under your car. Then look after the cat on the exhaust. Is there a plugged hole? Chances are someone replaced your cat with a '95/96 cat.

 

i have no O2's behind the cat or in the cat in my 99.

 

Hmmm? Ok maybe I'm missing something here. Shouldn't 'all' stock exhaust piping 4th gens have a rear o2 sensor?

 

Correct - mine does at least cause it went two weeks ago.