Check Engine Code P0420

I had the check engine light come on last night so I did a scan and came up with code P0420.
A quick search shows it’s probably an 02 sensor or catalytic converter.
Does anyone have any experience with this code or recommendations?

 

I would get this code occasionally on my jeep wj w/ the 4.7 v8. It occurred after I replaced the stock intake with k&n cold air intake kit. Eventually used a spacer in-line with the o2 sensors to get them a little further away from the exhaust stream and that seemed to cure the problem.

 

Interesting!
My 09 has a 5.7 and no engine mods other than a 5 year old DD cat back and I did the OV tune a couple months ago.

 

Hmm. I’d look into that tune. I never had my Jeep into a shop to properly diagnose as the code was simply a nuisance and the Jeep ran tip-top it’s whole life. Engine only had 40k. I’d always assumed it was just excess air or exhaust from the k&n. There’s a method to test your cats using a hand held infrared thermometer, something about one side being hotter than the other side indicates a cat issue...

 

Thanks for the replies.
I’ve heard of the cat test. Get the truck up to operating temp and test both sides of the cat with an infrared thermometer. There shouldn’t be a big difference in temp is my understanding.

 

My truck throws that code every so often but then it clears itself after about a week of driving

 

I cleared the code with TechStream and the light didn’t come back on for my short drive to work this am.
We’ll see what happens, I don’t think I’ve seen the end of this.

 

The first time I cleared the code it stayed away for about 4-5 months and that's been the recurring cycle. Once it stays on I'll probably change the o2 sensor and try and pinpoint the problem.