Hey guys, I've done some searching, but I found nothing.

There is a plug in the rear of the left exhaust manifold on my 1991 F150 302. This little guy decided yesterday to strike out on his own and leave me and the rest of the truck behind. Does anyone know what size this thing was?

Thanks in advance --

 

If it's a standard O2 sensor bung, it will be 18 x 1.5 mm, and you'll need an O2 sensor block-off plug since it is not a tapered thread. I'm not sure that the hole you have is for that unless it's a replacement exhaust manifold that will fit a newer truck too.

 

It is a replacement manifold. Do you know where I can get one of these plugs? I am having zero luck finding one.

Thanks for the answer.

 

Here is what a little internet searching pulled up.
O2 Bungs & Plugs, 02 bung Plug, RPS-o2plug | RacePartSolutions.com
Not sure if you could find this locally. Probably a race shop would have them.

 

"Bung" was the magic word missing from my searches. Thanks for the help.

As an update, NAPA has a metric oil plug that worked great. It is part number BK7041037.

Good times.