Bought a 3" resonated test pipe and need a bung welded into it for my o2 sensor. What size bung do I need?

Thanks

 

the WB or the stock one? the aftermkt WB is 18mm...i think 18X1.5 or something.

 

Just the stock one. Through a search the only thing I found was 18x1.5 but I think that is too big, the rear cat sensor is smaller than the front two I believe

 

not exactly sure of the 4th gen one...but the 3rd gen one is A LOT smaller than 18mm.

try giving Dallas at warpspeed a call...they make Y pipes all day and he should be able to give you that info fast.

 

you can buy the bung from lyell exhaust/budget they have them on there site for sale of course budgetexhaust.com click on lyell i think its under specialty parts or somthing go look youll see

 

18mm is way to big. 14mm sounds about right to me. I would also like to know this because I'm doing exhaust within the month.

 

I think I am way lost about this whole o2 sensor thing. I already have the Stillen y-pipe, a CustomMAx racing straight pipe, and just ordered a Budget b-pipe. I have never messed with o2 sensors. Am I going to have to when I put my b-pipe on, or should I have done something when i replaced my cat?