To get right to the question. After just over 130,000 miles on my 2013 F-150 5.0L V8 Super Crew 5.5' bed I have a DTC PO420 check engine light come on my truck in 2018. What, if any, harm might come of my F-150 if when the CHECK ENGINE light comes on with the DTC PO420 is found to be present I would use my DTC code reader to clear the code, turn off the CHECK ENGINE light and just keep driving the truck? For the past many miles I've had this issue with the Engine light and DTC I've done just that clear the code then drive on. Thanks guys for any help.

 

https://www.fixdapp.com/blog/p0420-ford/

 

My 13 5.0 had the same code plus Po0430(had about 200,000 on it ) Eventually the exhaust really started stinking.....then I believed what my mechanic kept telling me (plugged cats).....so after initially replacing oxy sensor to no avail I replaced the cats....That also didn't get rid of the codes either. but smell was gone...On advice from my mechanic I purchased 4 cat bungs off e-bay (around $20.00).....All they do is extend/keep sensors out & away from exhaust pipes.....but codes are gone & trk runs peach.
I spent approx.. $900.cdn to get to above.......

 

The catalyst efficiency codes do not mean that the cat is plugged, melted, or busted. If there are no engine performance issues (misfires, running rich, loss of power, etc), the codes simply mean that the converter is no longer converting as intended. At that stage, it's purely an emissions problem. If you're subject to emissions compliance testing, you will fail the test.

If the catalyst substrate has also experienced mechanical failure (melting, breakage, etc), the odds of a restriction of the exhaust is high and engine performance will suffer as it won't be able to "breathe".