so Yesterday I went to replace the two upstream 02 sensors and one came out easy as pie and then the other I think the last owner replaced at some point but used loctite instead of antiseize like a dumb *** because the threads on it are f***ed.... I cant find a place to get a new bung( I went to at least 8 places yesterday looking) What should I do????? try and retap it? If so then what size is it???? It looks like 18m but not sure. I have a welder so replacing the bung would be easiest if I can find where to get one but I could go buy a tap and die set if I really have to I guess... any advice? I found a place online I can buy a new bung but its 8 bucks plus 10 shipping, plus I have to wait for it, so 20 bucks for a piece so small and the truck cant be driven till I get the part...... this cant be my only option....

 

The threads on my 2000 model is 18mm. You can buy just an 18mm tap and "chase" the threads. Just to be sure if this is the same thread pitch for your truck, simply go to the parts store and have them pull the correct O2 sensor for your Blazer and the details should be given on their computer or the box that the part came in. (This is how I found out for mine.) Hope this helps.

 

everyone at the parts stores I have been to are complete idiots. They probably cant even do a simple oil change. They say that they have no details on the part except a part number.

So you say its 18mm, thats cool thats what I thought it looked like but the problem is the thread..... is it 1.5, 2mm etc.... I am guessing 18mmx1.5 but If I thread it wrong then I am f***ed and will still need to cut the old bung out and weld a new one in. I would of thought that someone on here has had to re tap the bung and would know what size it is thats the only reason I posted the question on here.

 

18x1.5 is the correct thread for the O2 sensor. StreetPerformance.com has the weld on O2 sensor bungs for $16. Others are available on eBay for cheaper.

 

thanks swart

as always you came threw with the answer.