Every how many miles do Catalytic Convertors need to be replaced? I was told 100,000 is this true?

And what are some signs cats need to be changed?

 

I've heard 80,000 - 100,000. But do they really NEED to be replaced? No. Only if you're having problems with them.

However, if you're not having any problems I'd run 'em to 125,000 if you wanted to be in tip top shape. Heck, I had stock cats on my 3.0L Ranger at 155,000 with no problems.

- decreased gas mileage
- markedly decreased low rpm power
- engine runs a little hotter than normal at constant cruising speeds
- exhaust leaks near header that won't seal in spite of new gaskets
- bucking or hesitation while accelerating
- cat's exterior surface temp cooler near outlet

 

Not familiar with any 'set' mileage parameters. The two vehicles I've had that plugged the cats didn't do so until the 150-200K miles range.

I suppose the scientific way is to tap a test port in the head pipe and measure backpressure for given RPMs. Surely Ford has some criteria for this.

Newer vehicles with pre- and post-cat O2 sensors will trip a fault code if the cat isn't doing its job. This measures the cat's chemical reaction properties. Not really a big concern other than passing emissions inspections.

I suggest to monitor your truck performance. If it starts having troubles with power under load or running up into the higher RPM ranges - this could be a sign that the cat is plugging to the point of reducing performance.

Another quick-n-dirty check is to place your hand at the exhaust - should feel a slight pulsing coinciding with the cylinder firing. If it's just a steady flow, cat may be worth checking out further.

 

Around here it doesn't matter how many miles you have on them. The thieves have been stealing them off of several vehicles. It was just on the news a couple of nights ago. There are several metals in them and they, the thieves are getting big money for them.

 

what part of MO are you from???

 

Northwest MO in St Joseph

 

Cats should last the lifetime of your vehicle...
You know they're bad if you hear the rattle, cant hit top speed, or if it feels like your driving an Manual and the clutch is slipping..

 

I agree with HE above.

I've never replaced a cat in any vehicle I've owned.

No need to...

 

Grub, I had an old '77 MB with 600,000miles...original cats...
if anyone is noticing broken up or clogged cats ..check the flollowing...
Melting (a cat) can only be actual raw unburned (liquid) fuel hitting the cat(s)...
fouled plug, shorted / open wire, cracked cap, arcing rotor or weak coil, burned exhaust valve.
Super Lean will also raise the exhaust temp to melting point. vacuum leaks, leaky EGR valve, low fuel pressure, clogged injectors.
Even if you gut the cat, its still not running right...

 

ive got 200,000 miles on my truck and i get horrible gas mileage. could it be that my cats are clogged?

 

Yeah they have been doing that in parts of MN too!! *******ing people that dont want to get real jobs..

What they do is cut them off and sell them to a metal recycling shop.. The shops pay pretty big bucks for them cause the CATS have platinum and other precious metals in them.. I hear they get around 80-150 bucks a CAT!!!

If I saw someone under my truck cutting em out, oh god only knows what i might do

-Alex

 

if they are paying that much for cats, then I am cutting mine off to fund my entire exhaust project lol

 

I doubt it. When I removed my old ones because the housing cracked (pass side) - They were clear - both sides looked great!! That was around 220,000 miles..

 

crap if there worth that much i got jacked at the place i went for my down pipes he said 100 for both down pipes and front o2s drilled and gave me 20.00$$ off if they could keep the cats. grrr

 

So where do you take your old CAT'S to ?? I have my old rears in tact . A recycle yard ?