I'm new here - did a basic search before posting but didn't see anything directly related to my issue.

New to me 2017 Cherokee Limited - with 2.4L. CEL on, P0420... did a little research and changed the upstream O2 sensor a few weeks ago.

After a few weeks with no CEL I figured I was alright but tonight it returned. Same code - P0420.

Looking through the freeze frame data (there are two sets of data stored) the Intake Air Temperature is showing as 215 C in both sets of data (image attached).

I can't help but feel that this is related to the code.

I took it for a drive while plotting the outside temp and IAT (Image attached)... looked normal. So I am thinking I will change the IAT sensor and see if this corrects the (intermittent?) problem.

Has anyone seen anything like this before?





​​​​​​​

 

Sounds logical.. I think you are on track with the IAT sensor replacement. Let us know how it goes!