Bolt size for rear o2's??
 

had the rear o2's disabled, what's the bolt size? need to fill the hole, thanks

I think it's 18mm but I am not absolutly sure. If you have a Napa near you they will be able to get you fixed up. Just take an O2 with you and they will be able to find what you are looking for.

there are also plugs that are like that of the big fleeze plug in the block that use can use, I would not use a bolt.

Why not just use the old o2 sensors, they're free, and you have them(I'm guessing), just don't hook up the wires

but an O2 would slightly restrict flow because it sticks out into the pipe, lol, just kidding, but it is true. Contact Stainless Works, ask for Al, they have the correct plugs in 304 stainless, and they have zero depth to the inside.

it's a vette, having Kooks on the car makes for a tight fit on the wiring, i'll have to match the threads, suprised nobody has the spec on the thread size?

I am not positive, but I think they are 18mm x 1.5, but please check before you buy something

your right, M18x1.5, no shops around here have that size, the commercial plumbing w/h's only deal w/ npt and american

Try Earls, I think they make an AN plug in that size

found some at ACE hardware a while back