I've been having fun with the 'maybe bad cat' P0420 DTC, fun, really!

A few months ago it popped up for the first time ever, three times in a week (I have a scan tool to clear it, 98,000 on the truck). So, per all the rhetoric here, I ordered the two O2 sensors. I had not seen the code since the three in a row, so I procrastinated a few weeks putting them in. I then had to drag my trailer with Jeep 750 miles to Moab, which went perfectly. So, having not seen the code for 1000 miles now, and pretty sure one of the two I sensors ordered might be wrong anyway, I sent them back to Rock Auto unused.

A day later the 420 comes back! Once, that was a week ago.

I figure at this rate I can live with it a bit. I was thinking of swapping out the full exhaust, including getting headers and a 3" cat-back, so I may just wait on the sensors until the wallet decides to green light that whole project.

 

Could just be the connections. Unplug them and reinsert a few times and look for corrosion. You have been driving in a lot of water lately from the weather, and sometimes that will trigger the O2 codes.