Do the headers on 2001 500EFI have ports for oxygen sensors?

I have the factory CMIs and am building a 540 to replace the 500EFI. I want to reuse the headers and use EFI on the 540 but with out a place for a wideband O2 sensor I will have to rething my plan as a new set of headers will add $5K.

you can add the 02 bungs to the headers, there not in them from the factory.........I added them to my CMI sweeper headers for dyno testing

That is what I was afraid of. To weld in oxygen sensor bungs properly, the headers will need to be normalized/stress relieved and pressure tested after welding. Thinking there will not be any change from $500 for that job.....

Thanks for the info !!!

500? If I could get that much I wouldn't do anything else. Do 2 sets a day before lunch and be enjoying my afternoons more

Ok so what is reasonable to put the bungs in both headers again with pressure test and stress relieving/normalizing ??

About 150 is fair for the hour and a half it would take

We put the 02 sensors in the tailpipes near the header tailpipe gasket cmi can do it for you ,i think they charge around 150

Send them in to CMI. They will purge the header, acid the welds & pressure check them. Taking them to someone who doesn't know what they are doing will cost you a motor.

added 2 at diff locations to my lightnings

I recently posted a thread with some pics of bungs being welded in a set of tailpipes. I would suggest putting them in the tails instead of the headers. It's much easier to deal with the tails. We put them as close to the flange as possible. Do a search on here and you should be able to find the thread. It was posted a few months ago.

Just for reference, we get $100 per pipe. That's $25 for the bung and plug (SS) and $75 to weld it. We polish the pipe after welding so that it looks the same as it did before we welded on it. Obviously, we pressure test them as well. So, a bung in each pipe on a singe would be $200.
Eddie