[Expedition_mike]

Backstory: I was driving down the highway when check engine light came on. Connected to OBDII and shows a P0430 catalyst System Efficiency Below Threshold bank 2 (driver side). So I replaced downstream O2 sensor and cleared the code. Unfortunately for me it came back 2 days later. Cleared again and came back 1 day later. 2018 expedition max 3.5 ecoboost has about 90,000 miles on it. Seems like an early failure for a catalytic converter. I don’t want to spend the money on a new catalytic converter. Can I drive it like this without damaging the vehicle? Or is there any other cheaper fixes for this? Thanks in advance for the help. -mike

 

[Expedition_mike]

My cats failed on my 2019 at less than 20k miles.

What do you think is causing these early failures? I have a 1996 Toyota with original cats that pass emissions with no problem

 

[Expedition_mike]

Mine is bone stock failed at 90k