Hello, I have a 2014 Ford Explorer with 250k mostly highway miles. I have maintained my vehicle well with oil changes every 5k miles, transmission flushes every 60K, etc. I proactively had the water pump and timing chain replaced at 220k and replaced the PTU as well due to a leak. I started occasionally receiving a PO0430 error when driving in the mountains with elevation changes. Then it started happening during city driving from time to time but mostly when it's raining or damp It does not happen when I am driving on the freeway. The dealer where I have been having my vehicle repaired says the catalytic converters need to be replaced. Trying to decide whether it is worth it but also wondering if there is something else that could be causing this like spark plugs or a coil. I have not noticed any performance issues or changes in fuel economy. Thank you.

 

A capable scan tool to monitor fuel trims can verify if the converters are not doing their job.. Any other way would be guessing. Did the vehicle anytime in the past have a misfire problem, if so it could hasten converter replacement