I was getting code P0140, bank1 o2 sensor 2 no activity, which is the rear O2 sensor on the drivers side. I converted to single cat with MAC headers, so I'm running O2 sims on both sides. Cleared the code, reseated the sim and verified the LED was flashing....code came back after 3 drive cycles. Swapped the sims from side to side and got code P0160 for bank 2, so the problem followed the sim. Ordered a new sim, installed it this morning, cleared the code and it came back on the way into work. What gives??? Don't want to blow more money ordering another one, but can't think of what else it could be.....

 

I've no solution regarding the O2 sims. Hopefully, you can return them?

If so, I'd recommend getting a tuner to remove the rear O2's programming code from the PCM. That's what I am having done.
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Ronnie

 

I have a tuned OBD1 computer, but I'm running the stock OBDII right now 'cause I'm trying to pass emissions. This is really the only thing holding me back at this point....

I've talked to the vendor I purchased them from and they said I could return them and they would send 'em back to their supplier. If the supplier warrantied them, they would refund my money. I'm not too worried about that right now, just trying to figure out how to get this fixed so I can pass emissions. I'm thinking that the likelihood of getting two bad sims in a row is low but possible.....just trying to think of anything else to check before I try ordering yet another sim.

 

Another option would be to have another O2 bung welded into the exhaust. Sounds cumbersome but it should work.

PCMFORLESS has assured me that their program will negate the rear O2 sensors and still pass Texas emissions. I hope so, I should find out next week or so.
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R