just put a set of mil eliminators on my 96 stang gt. reset ecu everything was good. about 30 miles later came back on. i checked code it is a circuit failure on the rear passenger side. ant idea what would cause this? sensor shot?
Check and make sure that no where on the wires are cut and or damaged.. Then make sure that you have them plugged in 100% (not saying that you didnt but just going over everything).. make sure that the connection on the insides of both the MIL and your sensor are clear of crap and that they can have a good connection..
Then as silly as this sounds, swap the senors (at least i dont think that there was a left and right one) and see if it will trigger the LEFT side one then you can know that its the MIL and not your sensor..
Good luck and post when you figure it out..
If you didn't get that same code before my guess is a loose connection when you put in the O2 simulators (MIL's). There is an outside chance the the simulator is bad from the factory.
Try the connections first and reset the code. If it comes back swap the O2 sims and see if it swaps sides. If it doesn't then swap the O2 sensors themselves.
I had the same problem when I first installed my MILs. Turns out I didn't have them pressed in completely. You should hear a click when you have them in there all the way, that tells you they are seated properly. I was getting a SES code after I drove around for about 10min, and I was like WTF? Checked the connections/seats and found one to be loose. Kinda of a dee-teh-dee stoopid moment for me. Check this first, then you can rule that out. If they are seated good then you might have some bad MILs.