when u get rid of the cat how much gain in hp and torq will u get ?

on a 04 3500 D/A

Maybe 3 rwhp

Not enough to make it worth the pollution police

Not enough to make it worth the pollution police

........or the effort or energy involved in taking it off!!

the sound is great though IMO

It IS worth getting rid of so it doesn't plug on you, IMO, and it WILL. Just a matter of when, not if. Within two years, the cat on my grandfather's '97 Cummins plugged while he was pulling his trailer from Alaska to New York. Hasn't had a cat since.

I have customer that have over 100K on them without trouble. Most of there mileage is all towing so they seem to be holding up well on the Duramax. Removing the cat will give the exhaust more noise and spool the turbo quicker and may give an extra 50 deg. drop in EGT but all in all alot of work for very little if your not into racing the truck. In which case every last little bit helps!

All good points. ace777777777(?), there are plus's and minus's to removing the kitty. Just depends upon what you are going for? If you want a nice deep, throaty rumble and fast turbo spool up removing the kitty accomplishes this. If you are one to worry about being caught without the kitty then leave it on, likely not worth the anguish. ;)

We've had plenty, lots, mucho, heck a ton of discussions about this on the DP. Grab a cold one, do a search, and take in all the intel. I did this and ended up removing the CAT and installing a MBRP 4" cool dual exhaust. Doesn't sound like the same truck! IIRC the EGT reduction was greater than 50* though, but best to check. JJ :)

JJ: I know you're gonna' chew me out for not searching 1st, but (notice I'm asking my question anyway) If you change one thing in the emissions (cat removal, egr plate, etc.) Can GM void the whole emissions warrantee when (if) they find it? I'm thinking that puting the cat back on prior to taking it in for anything else would be onerous to say the least... (but I'd luv to take it off:rolleyes: )

I took mine off for about a while. I absolutly loved it, the turbo spooled up quicker and was much louder, lower EGT's of coarse, and the exhaust smelled like a diesel should! But living in Southern Cal i thought it was just not worth the risk. I would pretty much say any dealer would not be happy too see that you have removed the cat, or there being sighns of having the cat removed (egr blocker/fingerstick) if they noticed them or knew what they were. Some say there is nothing to worry about around here not having a cat, but i just like to play it safe. I have been informed about the new clean immisions act, where you can be fined up to $31,000 :eek: now thats what i call it when the government interfers too much with our lives!!! -:t -:t -:t . good luck!

moving to correct forum. Please try and post in the corresponding sections. Thanks

I have been informed about the new clean immisions act, where you can be fined up to $31,000 :eek: now thats what i call it when the government interfers too much with our lives!!! -:t -:t -:t . good luck!

For $31k, they can keep the truck.

Which states make diesels do emission testing ?

How else would they catch you, overzealous cop '?

Most cops have trucks and dont think they are going to get under and look. Most know diesels are louder (ex. a stock Dodge or Ford) than gassers. There are too many ricers out there to pick on anyway.


Just my opinion.


LATER!

i didnt cut the cat off ,i had it gutted, i got the honey comb chised out ,i took it to a muffler shop and for 50 they cut a square in it chisled it out then welded the squared metal back on ,they filled up a box of crud that came out of it . i had my truck on hyperteck level2 it felt like it was on level 3 after the guts where removed . i still have the cat on so i cant get in trouble and truck runs and sounds soo much better now . didnt blow any codes , ets are lower now i can tow in level 3 under 1200 ets going up hill with a 13000 load i can go above 45 mph ets are under 1200.

it feels like it has lots more hp and torq

it runs like differnt truck ,they filled up a box 16in long 8 in high half way ,thats how much stuff is stuffed in a cat, i tooka piece of that honey comb ,u coulnt even see through the holes , i held it up to the sky just to see through the little holes. i was shocked ,its such a restriction the engine runs easier ,it can breath now