Thank you I actually ended up ordering as they looked more precise than the foulers and got them in the mail today, they seem of high quality and should do the trick for the downstream sensors.
UPDATE to this thread. Sorry iv been busy working on the jeep. I have one motor stripped down ready to be pulled and the next is almost ready to be pulled and painted. (Iv been saving pictures to start a separate thread)
I may have found a solution that may deserve a writeup later down the line, I'm waiting for tomorrow to call this custom exhaust place and another member from another forum that did the same thing to respond before I give give it my effort.
it's simply welding the upstream bungs into only cylinder 1 and cylinder 6.
It doesn't involve buying an expensive header and cancels out having to buy a header that has the 02 sensors welded into each bank. But iv yet to hear back on what exactly it affects I just know iv seen a build thread where it didn't throw any codes. Hell the dude didn't even use 02 simulators he just put the downstream 02 sensors farther back and it still didn't throw a cod until one of them went bad.
I want to know if it affects fuel trim or is just setup that way to diagnose problems easier. If it's the second option I'm going to do it.
I thought it was all figured out and i could move on but when I started looking for a header that would fit a 97 4.0 I started to find that the only ones that had bungs or enough space past where the 3 tubes convert into one were either way too much or way too cheap/low quality.
The problem is nobody makes decent headers for a mid price point that would work for swapping pre 99 engines into 2000+ xjs so I was finding that'll I either had to buy a pre 99 or a post 99 header.
The difference is pre 99 is only one downpipe tube
2000+ headers have a split downpipe and smaller diameter head to header inlet than the 97-99 engine I was swapping in.
The entire point of this whole thing is I don't want the excessive heat the precats generate and to eliminate chokepoints on my exhaust system
that lead me realizing spending 500$ on a header was not worth investing into until maybe after I was done with other modifications that were more important to me. But....... that still remains to be seen.
My plan for now is to simply use the exhaust manifold from the 97 and weld in the 02 sensors because the way the tubes are setup is exactly as the 2000+ are and even includes a more header like design here is plenty of space to do so and give it the same setup as stock minus the precats.
but if I end up finding an answer to exactly what having it set up like I mentioned above with the o2 sensors on cylinder 1& 6 I may end up saving that money before I waste 50$ having a shop weld the bungs to the stock exhaust and go ahead and just have it done to a header.