Im ordering a set of AC Delco O2 sensors to replace these Bosch's that keep throwing codes at me. When I installed them after the header install, one went in very tight the whole way. I think I got some slag in there when welding the buns in. I think Im gonna have to take a torch to it to get the old one out, but I want to run a tap through there befor replacing them with new sensors.

Anyone know the thread size so I can go buy a tap?

 

You welded your buns?

18mm..... or is it 16?

 

Anyone else?

 

18 X 1.5

Tyler