If a vehicle is in a proper state of tune, how many miles on average before the cat converter is clogged and needs to be replaced?

 

since you have a four by four I'd have to ask the question if you go off roading? the constant jarring will affect the life of it...but on average a cat should last over 80000 miles with correct maintenance of the engine.. but of course there are other vaiables that affect it ..towing and high performance racing will also affect it as well as the quality of gas that you use

 

Hey thanks for the info. My truck has 141,000 on it, I'm starting to suspect my pre-cat isn't up to par. My truck just doesn't seem like it wants to rev much lately, and my fuel mileage has taken a drop over the last several months.

 

my cat was clogged at around 110k, partially due to running with a bad o2 sensor for a while
Matt

 

Wow thats it i thought that they would last longer so on 03 i would have to replace all 4? bummer.

John

 

well mine ran with a bad o2 sensor and a 180 degree thermostat, both of which will cause the engine to run improperly and carbon up the cats. My front one was quite black. If you go to a-1mufflers.com (go to the catalytic converter link) they have a diagnosis chart that shows why cats fail early. Otherwise they should last 200k I think.

 

and many places ( I know dynomax had one for my truck) have replacement kits that replace the 2 inline catalytic converters (4 if you have dual) with 1 (2 if you have dual). The exhaust pipes aren't as clean afterwards, but it flows a bit better I think. To replace my single exhaust ran 229 for parts (I bought myself) and 150 for labor to install.