Catyltic removal, Cat removal

[MStrain]

Has anyone removed the cat on thier third gen trucks? How much of a performance gain did you get? How much louder? Better mileage? MBRP makes a cat test pipe, it is a little pricey for a piece of bent tubing, but it should be a direct fit.

 

[2broke2smoke]

yep we did ours by just beating the center ceramics out with a piece of pipe and a sledge ...



4" straight pipe that is federally "legal" ...



i did ours the first day we brought it home so i can't tell you the improvements but we averaged 17. 8 mpg for the first 12k miles ...



it's at 26k now with no problems ...

 

[Hoefler]

Turbo will spool quicker, the exhaust runs cooler.

 

[MGreer]

My kitty ran away yesterday, so I put in a delete pipe last night. I haven't ran the truck yet to see the difference. I used the AFE pipe from DPP. It is a direct fit and costs less than the MBRP. I did a magnet test to stock, mbrp and the afe pipes and they all stuck the same. I would go with the AFE.

I will post back when I get some mileage numbers.

 

[MStrain]

So did anyone notice a big increase in exhaust noise?

 

[SKneeland]

for less than $100 any muffler shop can cut out the cat & muffler and replace with a piece of 4" pipe.



its loud as hell cruising around town , but surprisingly quiet at highway speed

 

[SNoyes]

M Strain,



Are you in LA, Cali? If so, I would imagine they would be on the prowl for a diesel that's kitty ran away. I replaced my whole exhaust, turbo back with a 5 inch and eliminated the kitty on my 2006 mega cab. Notice maybe a little cooler temps, and I get a slight drone from the 5 inch on the highway. But I do sweat the cat delete, and am looking into a replacement 5 inch cat... BTW, anyone know of a company producing a 5 inch cat... .

 

[drewRoberts]

no cat. . . stock muffler. . . not much of a difference. maybe a little more 'growl' before the turbo spools, about 50F lower EGT's(maybe less) and the exhaust doesnt smell like a propane grill.

 

[SNoyes]

Yep...



The propane grill comment is spot on... LOL

 

[MGreer]

SNoyes



A member on here installed a 5 inch exhaust awhile back and used his stock cat. He sawed off each end of the cat until the openings fit the 5 inch pipe, then welded it together. He posted pictures but I dont remember what post.

Maybe someone can chime in. Hope this helps.

 

[AKaiser]

for less than $100 any muffler shop can cut out the cat & muffler and replace with a piece of 4" pipe.

But they won't. At least not around here. They would be fined heavily.

 

[CogginsP]

for less than $100 any muffler shop can cut out the cat & muffler and replace with a piece of 4" pipe.



its loud as hell cruising around town , but surprisingly quiet at highway speed

When I had to get some extra 4" pipe added on to my delete pipe (because it wasn't long enough) I had to drive it as is to a muffler shop and they HAPPENED to have a 4" peice of pipe. Now I am speaking for New Orleans, but most muffler shops don't have 4" peice of piping. First most of them don't have the ability to bend pipe that big, and second gassers (the type of vehicles muffler shops see 90% of the time) would never have 4" exhaust pipe on it. Biggest they will carry typically is 3". The only reason the muffler shop could do it for me was because they HAPPENED to have some extra 4" pipe from a powerstroke that they had done 2 weeks back .

 

[MStrain]

M Strain,



Are you in LA, Cali? If so, I would imagine they would be on the prowl for a diesel that's kitty ran away. I replaced my whole exhaust, turbo back with a 5 inch and eliminated the kitty on my 2006 mega cab. Notice maybe a little cooler temps, and I get a slight drone from the 5 inch on the highway. But I do sweat the cat delete, and am looking into a replacement 5 inch cat... BTW, anyone know of a company producing a 5 inch cat... .

Who would be on the prowl? I am not required to have any emmission testing in Cali, and I don't think the dealer will care, they aren't that smart anyway from my experience, that just leaves CHP, LAPD, and the Sheriffs dept, but I would imagine they aren't randomly doing Cat checks on CTD's. The only reason I want to do it is to hopefully increase mileage, maybe a little more power/throttle response, but I don't want a ton of noise, I have an aeroturbine which is really loud as it is. I am strongly considering ditching the aeroturbine for a RokkTech. I have also heard that the Cat's on these trucks don't make that big of a difference as far as cleaning up the exhaust and decreasing emmissions, any input on any of this would be helpfull.

 

[Mobius1]

I cut the cat out of my truck. Not really any performance gain (at least from SOTP) I didn't really see any milage increase. EGT's did drop slightly, And crusing at highway speeds is suprisingly quiet, however when I stop on it it sounds SWEET!! A lot more throaty, also it smells like a diesel. Just be realy careful if you decide to do it. They are illegal to remove.

 

[PRattenbury]

M Strain,



Are you in LA, Cali? If so, I would imagine they would be on the prowl for a diesel that's kitty ran away. I replaced my whole exhaust, turbo back with a 5 inch and eliminated the kitty on my 2006 mega cab. Notice maybe a little cooler temps, and I get a slight drone from the 5 inch on the highway. But I do sweat the cat delete, and am looking into a replacement 5 inch cat... BTW, anyone know of a company producing a 5 inch cat... .

Maybe check out Random Technologies?

 

[SNoyes]

MStrain,



Yea, I thought Cali would be one of the first with some sort of emissions testing on diesels, but if they don't then getting caught would be kinda a crap shoot. If you get pulled over for something else, they may add stuff on. Had a buddy pulled over for expired tags, which he had the new ones with him he just forgot to stick them on the plate. They got him for tires beyond wheel wells, lift too high, and exhaust too loud. Also tagged him for tint too dark, so I figure they could, on a random bad day hit you with the cat delete (which I hear is a $2500-$10,000 fine). But your absolutely right, they aren't looking for that at all... .

 

[Cattletrkr]

No EGT reduction
No better mpg
Worse towing drone
Spool-up unchanged
Sounds better, but not worth it

I've thought about putting mine back in but it's not worth the effort. They are so non-obstructive there is no reason to remove it in the first place. Leave the cat and remove the muffler if you have to change something.

 

[MStrain]

Thats the kind of feedback I was looking for, I don't want extra noise, I was hoping it may increase mileage/hp, but I am also a person who tries to be environmentally friendly. There is enough pollution in the world and I try to minimize my impact, I will probably just leave the Cat alone, LA has enough smog as is.

 

[granduer]

I had removed mine about 4 months ago. I was getting about 19mpg proir to removing and now it is down to 15mpg. As far as performance it didn't help at all. I am going to put mine back on because the loss in MPG's isn't worth it. Just my 2 cents

 

[Joseph Donnelly]

I recommended the early 2004 to people who told me they would wait for 2004. 5 to get the 325 HP engine. Now they realize the cam timing is worse, mpg lower, and the cat may be restrictive if it gets plugged with soot from the power they added. After people playing "great smoke stories" for years, now the EPA is rabid about emissions equipment and fining companies (so far; owners might be next).