Catalytic converter to tailpipe bolt size????

[witchdoctor813]

About to change out converter for test pipe with dump. Anyone happen to know the size of the four bolts needed on the backside going to tailpipes??

 

[michael evans]

18mm. I think

 

[Chuck Leeper]

AIRC, the oem converter had studs in it. When removing it, you end up w/ holes in both sides. You can use 3/8" bolts/nuts. I'd use all steel self locking nuts.

 

[Nick Micale]

The stock cat has 10mm studs, and the nuts are a 15mm hex.

Like what Chuck said, you can use 3/8" bolts and nuts for the dump pipe.

 

[michael evans]

My car had bolts (18mm) on it when I got it, but I removed the converter (what was left of it) and installed a test tube like the OP is going to do.