I am looking for the weld on flanges to put on my new stainless exhaust i have recently welded up. I need them to fit the flanges on the toyota 02 sensors, more specifically the front AFR sensor on a 1999 cali spec 4runner. Need 2, where should i look, is it possible to even get them?

 

I couldn't find any, URD claimed they were going to have some made at one time. I made one from scratch and refurbished another one, see post #177 on page 8 here:
https://www.yotatech.com/forums/show...4+swap+started

 

I'd try an exhaust shop (midas, mineke, custom exhaust shop, etc) and see if the can get flange type bungs, I am sure someone makes them and they are available in the marketplace......but they are also alot less common since most O2 sensors on cars/trucks use the threaded type.

 

All the exhaust places and auto parts places I asked looked at me like I was crazy.

You might try this guy:
http://www.customtacos.com/forum/showthread.php?t=71236

But I think you still would need to tap for the studs.

 

I have gotten the same crazy look from a few exhaust guys and one had made his own by using 1/8" thick steel and making his own mounting studs. Seems like a lot of work. URD said they would get back to me when i called about 6 months ago about some flanges, but never did. Had a bad run of service with them and am not sure that i will be working with them anymore. I will try to get intouch with the guy that was mentioned above. I just got back from florida today so im a little behind schedule. Looks like i am getting a set of downey headers... is there a crossover pipe that i can buy that comes with one welded on? for a 1999 toyota 4 runner or am i better off making my own crossover and welding on a bung barring i can find one?

 

That quizzicle reaction seems to be pretty commom when asking about those flange bungs (reminds me of the old RCA dog, Nipper! lol!)

I had to refurbish mine from the Taco during my 3.4 conversion, since no one seemed to have them. At this point, I think the only hope of finding new ones would be to find out where Toyota sources them for their domestic factories.

 

I had one O'Rellys that thought they could order one in and said it would be $5 and even came with a new gasket. I got real excited and ordered it and when I went back to pick it up and they handed it to me I knew it wasn't what I needed but it took me awhile to figure out what it was. It was an adapter to convert from a OEM flanged O2 sensor to a universal (spark pulg type) sensor.