Do Cats Get Plugged?

[Cattletrkr]

I've had a Juice on my truck for about 100K of the 147k on the odo. In that time there has been more than a little smoke. I never removed the cat because I like my hearing just the way it is. I know it has been said here and elsewhere that the cat isn't as restrictive as the muffler. That's when they're both new. What about one with almost 150K on it and a lot of extra soot passing thru?



Has anybody out there gone as many chipped miles as I have and then removed the cat? What did you find?

 

[FordCummins]

They sure can get plugged up. I would bet that yours is with that many miles on. Id try pulling the cat to see how it runs/smokes without it.

 

[JFaughn]

Make a back pressure test port , something that will screw into the exhaust pipe in front of cat , and cap off later , up to 3-5 lbs [ thats with a load on eng. ] may be ok , if much higher , then pluged .

 

[Cattletrkr]

I might be able to couple something together and use the EGT port that's behind the turbo. Only I don't have a backpressure gauge. \



By "Load on the engine", do you mean high idle or towing at 60mph.

 

[CSnyder]

Here I thought I was gonna read something funny about kitty's. :-laf :-laf :-laf

 

[dpuckett]

Load on the engine normally means towing at 60mph in your case. Definitely not high idle. Get the boost gauge needle moving. Removing the cat and replacing it with a piece of pipe wont affect the noise level any. Might affect the tone, depending on the resonance and design of the cat, but the muffler should still keep the noise level down.



Daniel

 

[Jefff929]

Here I thought I was gonna read something funny about kitty's. :-laf :-laf :-laf

Rabbits get plugged that way too. :-laf Yep, glad to see someone else went there too.

 

[Cattletrkr]

Rabbits get plugged that way too. :-laf Yep, glad to see someone else went there too.

Why don't you both go plug yourselves. :-laf

 

[Hoefler]

On gassers, if there is more than a 1/2 lb of pressure difference from before the cat to after the cat, it is restricted or plugged. To check it, braze a 1/8 inch union to the pipe in front and behind the cat. Drill a hole through the union into the pipe. install a fitting for 1/8" copper tubing at least a foot long and adapt it to a gauge. Use a low pressure gauge, like a fuel pressure/vacuum gauge used on mechanical fuel pumps. Like what is said above, you need to drive it with a load to get your readings. When done, you can plug the holes with pipe plugs.

 

[Cattletrkr]

This is starting to sound like I'd be a lot better off just to cut the dang thing out and be done with it.



Has anyone ever tested theirs?

 

[dpuckett]

Unless you have a revenue enhancement "safety" inspection that requires it to be on there, I think you would.



DP

 

[Cattletrkr]

I do get inspected both annually and at random. But no one has ever crawled underneath to check for the presence of a cat. If they do I could probaly just confuse them and tell them that it is not an '04. 5 and say it's only an '04. I doubt they'd be intelligent enough to look at the engine sticker. Somehow the little sticker on my visor must have gotten dissolved by the sun.



EDIT: I was referring to a routine DOT inspection. MN dropped the smog checks when we voted Ventura into the Governors mansion.

 

[MChildress]

The cross support has a saddle in it for the cat. But your probably right they wouldn't notice. I have given this some thought also. My Smarty sure sends some smoke through the cat.

 

[CTD 600]

Sound wise removing the cat did increase the "drone" and "tone" of the exhaust. If you still have the OEM monster muffler on it then it wouldn't make much of a difference.



That being said... Lower EGT's and less back pressure would be the "cat's meow" if you removed it. Who wouldn't want that?



I saw a increase in fuel mileage after I removed it also, but i'm turbo back straight piped.

 

[Cattletrkr]

I inspected the innards of my cat tonight and it looked pretty good. A lot of black, but i wouldn't call it plugged. Of course since it looked good I did the EPA approved thing and reinstalled it. Truck sounds a little louder. I wonder if I didn't get the clamps tightened all the way. Hopefully it won't fall off all together.