P0420 and p0430 code Ford F150

Common Causes
Faulty Catalytic Converters: This is the most frequent cause, as the catalytic converter's precious metals become damaged and can't properly clean the exhaust gases.

Exhaust Leaks: Leaks in the exhaust system, including the manifold or pipes, can allow fresh air into the exhaust stream, giving false readings to the downstream oxygen sensors.

Bad Oxygen Sensors: The upstream and downstream oxygen sensors monitor the catalytic converter's performance. If a sensor is faulty, it can send incorrect data to the ECM, leading to a false code.

Engine Misfires: Engine misfires can lead to unburned fuel entering the catalytic converter, causing overheating and damage to its internal components.

Incorrect Air-Fuel Ratios: A mixture that is too rich or too lean can affect the catalytic converter's ability to function correctly and trigger these codes.

To get a better handle on the issue will probably need to run the vehicle on a scan tool not a code reader and see exactly what part is doing what

Avoid sitting and idling as much as possible.

Clear the code. Dump a can of berrymans b12 in the tank. Go get on the road and drive with the RPMs higher for a good bit. Over 3000 rpm for 10-15 miles. Just get on the interstate if need be and run at 70 in 3rd.

The higher exhaust temps will burn off the contaminates.

Code should stay off for a long time if you avoid idling.

I used to get on i10 and watch my temps post cat on scan tool. Over 700 and carbon ia burning off. Over 1000 and it's basically a self cleaning oven in those cats.

Literally just went through this like 3 weeks ago. Only had it on bank 2 at first. Had to get it fixed to get inspection completed for registration in my County in TX. Changed the Catalytic converter on bank 2, then I ended up with codes for the upstream O2 sensors. Shop I brought it to was honest enough to say I need to go to a different shop that had the right tools for a deeper diagnosis. I could spend another 500 and change the sensors just to find out it was a wiring harness or computer issue and that was the true issue the whole time. In the end, I paid for the diagnostic and they weren't sure at first, but after a few hours, they were confident it was those sensors. $1200 later ($500 cat conv., $200 diag., $500 O2 sensors) and it's all fixed. Just pointing it out that it could be deeper if both sides showing that they failed at the same time, at least that's why the shop pointed me to do a deeper dive before throwing money at it. But could also be a simple fix based on codes.

I ended up actually having two faulty O2 sensors. May have been what originally threw the catalytic code. And I have a local shop by my house that apparently does cheap work. I know they quoted half the price as another ship for the sensors