My 2005 FX4 SCREW just passed the 190k mark and the exhaust is bone stock. What is the general thinking on life expectancy of stock cats? The truck runs great with good power and fuel economy so i don't want to mess with it unless the cats are a ticking timebomb.

 

I have 33x,000 on my 4.2, it has original cats and passes calif smog no problem.

 

Ford just hopes and warrants them to 80k miles. Anything after that is good. Keep it maintained well and not running rich they will run a long time.

 

That's only because it's federal law.

 

If the vehicle is properly maintained, cats can last the life of the vehicle.