vintageman

Great job on the write up and pics. Thanks for posting this.

Tom

jtb

Glad to contribute to some folks and a site that have helped me many times.

Blckwlf

So, if I have a bad CAT, I don't have to cut and weld to replace? That's good to know.

How did you use a mallet to diagnose a bad CAT?

HulluCorn

They sell bolt on ready cats. Just have to search for them.

no welding as long as you buy a new clamp (preferably "ez-seal)

jtb

These cat replacements are essentially just replacing the middle part of your exhaust system, the part between your exhaust manifold and muffler. The wide flared-out front end of this catalytic converter pipe assembly fits onto and over the rounded, kind of "ball end" end of the exhaust manifold and is pulled tight against it with a flange clamp.....the quality of that fit and seal is critical, and there is no gasket to complete the seal. The aft end and the pipe connecting the two cats so they can go into a single muffler are essentially slip-fits with clamps.

Bear in mind that although the catalytic converter itself is maybe a foot long, fedex will be delivering two pipe setups, one about 3 feet long, and the other about 4 feet long with a 2 foot pipe sticking out off the side. They simply wrapped the ends and put a shipping label on them. Interestingly, shipping was only $35 for both complete assemblies.

There's also universal cats, which appear to be just the cat box with some ends that are either slip-fit clamped or welded.

I initially heard a rattle under the driver's side when stopped and in drive. It sounded like a marble bouncing around in something. Under the truck, I determined that the sound was coming from the driver's side cat.

You'll often read about folks removing parts of the heat shield around the catalytic converter itself. This is because that shield has become partially loose and is rattling. Or, a rock may get lodged between the cat and the heat shield and rattle.

I tapped on the side of the cat with a rubber mallet and heard the rattle when the truck was off. I removed the heat shield to confirm the diagnosis and again tapped it with the rubber mallet - still rattling.....a piece of the "matrix" inside the cat had broken off and was bouncing around inside: evidence of a failing or soon to fail cat.

Colt_55

Thank you for the write up. I just got the P0420 code so I need to replace my cats. I'm actually trying to sell the truck, so I don't want to dump a lot of money into it but I also don't want it to effect the next person I know you get what you pay for but is there anything wrong with the cats at this link? Also has any one used the product cataclean? I really appreciate any help. This forum has been a huge help.

http://www.autoanything.com/exhausts...id=10424-10188 2606093&productid=77442935888&gclid=CMTG896NvMkCFY s6gQodi9gGYQ