I hate writing posts that expose me for the total f***-up amateur that I am, but here goes...

I put on a whole new exhaust a few months ago (see sig). In the process, I took the an O2 sensor bung and the driver's side header to an exhaust shop and asked the guy to cut a hole and weld it in for me. My dumb *** didn't draw a cross hair on the exact spot I wanted it, so I get it back with a bung pointing straight at the crossmember, with like 1/2" clearance. Don't know of any O2 sensors that short . So besides needing another bung welded in a different spot (that went fine), I needed to plug up that hole - I found a pipe plug that kinda fit, taped the threads and put it in. Everything was happy until last week, when a "ping" underneath my car followed by a loud exhaust leak announced that the plug had worked itself out.

So, after not finding ANYTHING at local parts/hardware stores, I spent the better part of today cutting the threaded part off an old O2 sensor and soldering (dumb, I know, melts too low) a bolt down the middle, with a cotter pin through a hole I drilled holding the bolt to the threads. This installed great and tight and I was really proud of myself until, 10 miles from my garage, the thing came loose. The solder had all melted (probably coating my cat now ) and the threads, now spinning free of the bolt, had completely removed themselves from the header (~4 full revolutions!).

I dunno if anyone has ever had to fix a similar problem... but do you have a good idea of a way I can fix this for good? Thanks a bunch in advance.

 

could you just weld the hole shut?

 

Me, no. Someone else, I guess... maybe this is the only way. I was trying to avoid having to take it in somewhere b/c I don't have the time during the day and can't be w/o car right now... I guess maybe I'll just blow off classes etc. some day this week for a few hrs. and have it fixed

[1/15 Edit:]
I took it to a friend at his Car-X and he had a plug with the right threads (didn't know where to get em except via their parts supplier direct). He just screwed that in and arc-welded it into place, simple...