O2 housing dimensions?

[Enigma_Man]

I'm prepping for putting on my O2-back exhaust this week. It's a home-made affair with no cat I picked up cheap.

It has hangars that need to be re-welded into better spots, but that's all I know of.

What I'd really like to know is the size of the outlet of the stock 1G O2 sensor housing, and the spacing on the bolts. The downpipe section of the exhaust is 2.5 inches. I had assumed that a 2.5" gasket would be fine, and everything would line up, but now I'm worried How big can the O2 housing exit be hogged out to also (if it's smaller than 2.5 inches).

Thanks in advance!

-Jesse

 

[Wilsonman02]

I'd say stock is deffinitly smaller than 2.5 inches, probably 1.75 - 2.25. not really sure. I'd get it ported to 2.5 inches to match your downpipe, so you dont get boost creep.

 

[pneumo]

The stock O2 housing uses a 2" gasket. It can be bell ported to 2.5"

 

[jbillakdsm]

Yeah, you can get it out to 2.5" without too much trouble. Just be careful of your wall thicknesses and you should be fine. While you have it out and are working on it, you might as well do some porting to the wastegate runner to improve flow.