Around when does the cat usualy go bad?
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
depends on how it's been cared for. If it has been bottomed out and has been hit buy things, it could die with 100 miles on it.
If it has had a tank of leaded gas in it, bye bye cat.
I don't know of a rule of thumb, but they seem to start failing anywhere after about 120k miles.
If it has had a tank of leaded gas in it, bye bye cat.
I don't know of a rule of thumb, but they seem to start failing anywhere after about 120k miles.
Le Mans Master
Joined: Jul 2002
Posts: 5,818
Likes: 2
From: Alive and well in Burlington NC
It's really hard to put an age or mileage to them. The DS precat on my 91 started breaking loose and clogged the main at ~45,000. The cat on my 86 chevy pickup lasted untill 193,000 before it was replaced (2 weeks ago). No previous owners on the truck - I bought it new in 86.
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
There is no replacement schedule for them, they'll get clogged when the engine is being neglected, so it depends on the owner.
Mine are just fine at 141K.
Youll usually notice a sharp dropoff in power and sometimes alot more heat in the footwell area when they get clogged up.
Mine are just fine at 141K.
Youll usually notice a sharp dropoff in power and sometimes alot more heat in the footwell area when they get clogged up.
