IAT good, jeep still shows bad IAT

I've been getting a 23 code from my check engine light, and have tried replacing my IAT (MAT in my Haynes Manual) with another one pulled from salvage and a new one. I've also done the test ( IAT Sensor on the Jeep Wrangler YJs are easy to test and replace. ) and feel reasonably certain that the IAT sensor is not the problem. I also tried to clear my codes by disconnecting the positive battery terminal and letting it ground out for for a while. If it's not the IAT, what would be the next thing to check? I'm not throwing any other codes except the usual - 12, 33 then 23 then 55. Thanks for any help