1990 244 DL

In stewing about my current problem of having a '90 exhaust system with a blown header pipe and other holes, I was trying to transplant a complete '86 exhaust, only to find that there is no O2 port in either the header pipe or the cat.

I haven't been able to find a header pipe or cat with an O2 sensor hole locally available (for expediency, as Junior is up on the lift at the mechanic's), so my NAPA guys made an interesting suggestion. They suggested cutting a hole and welding a jam nut onto the pipe to insert the O2 sensor. Evidently, it is a common solution to this problem on other makes of vehicles.

On the current system, the O2 port is located immediately after the header/cat junction, on the bulge. The system I am trying to transplant looks to have a similar setup, but I'm not sure if drilling a hole in the same spot would actually get me to where I need to be, as I don't know the internal diagram of the cat's structure.

Would drilling a hole either there or at the very end of the header pipe be the better viable solution?

I've already done this to my oil pan with some welding help, as PO scrunched the plug and stripped out the threads, and my helper has graciously offered assistance again. That, and the systems are off the cars, so I don't have to worry about unplugging all the electrical components!

Any suggestions are appreciated!

I think I can, I think I can, I think I can get Junior on the road!
ezsha


Thanks
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'84 244, Peter, never drove. Robbed to fix Paul, '86 244 - drove for 2 years; holey saint now, passing parts to Paul Jr, '90 244, yet to drive. Friends w/ '90 245, jokingly aka Mary, (pregnant sedan & completes PPM trilogy). Daughter to unnamed '90 745.