I just got greddy cat back..
it has a hole for the O2 sensor
my car does not use one there
any idea where i can get a plug
for this damm hole..
i went to a couple auto parts
store and all they have is 1/4 and
this is close in size but will not
go into the threads..so im guessing
its of course metric. i also went to
home depot and found a bolt that was
way too long and the threads were too wide.. any ideas?

 

on the pipe after the main catalytic? Is yours a 49 state model? You can give GReddy a call and ask them the size to make life easier... Stillen might sell these bungs as well.

 

You should have a 3rd o2 sensor, the 95-96 models had only two.

Anyway, I have a 97-99 Greddy on my 95. I went to the Nissan dealer and got a bad sensor from one of the mechanics to plug the hole. IIRC, the threads are a metric pipe thread (tapered).

 

I do have three but they are all before the cat ... wish i had a bad sensor laying around .. grrr

 

Yup, there is an o2 sensor hole and the 99's do NOT have an o2 sensor there. All I did was have that hole welded shut. I would have put a o2 plug but the shop I was at didn't have an extra one so I told them to tach weld it shut. No problems with it besides it's a little uglier, but you don't see that part anyway.