CD in NM

I live where there are no inspections - emissions or otherwise, a few counties in New Mexico DO have emissions inspection - truth is, it makes no difference what county or state your vehicle is registered - DOT is FEDERAL, highways are governed under the federal regulations - you are required to meet the federal standards when going down the road. If your vehicle came from the manufacturer equipped with a CAT, it better be ON the vehicle. The EPA is strongly pushing the DOT to enforce the emissions laws. One thing to gut it out and decieve them, another to remove it entirely. If they suspect that you have a problem with your CAT, they actually have some kind of portable testing unit they can use to test it. The new regs regarding this stuff tighten up in 2010, I look for lots of vehicles to be in the DOT pullovers being looked at, lots of them. They have hammered the commercial vehicles pretty hard, now you are seeing more and more private vehicles in the pullovers. It's the trickle-down effect, and soon everyone will get a taste of it.

To me, removing the CAT is not WORTH the problems it can cause. I'd rather spend my money on maiintenance/mods than on fines. Remove the muffler, that's where you will see fuel mileage gains, and that's really only maybe 1-2 mpg at best.



CD

cromulius

And is it not less pollution with the cat on? Pollution is not cool in my book.

thames1948

I like the cat. It smells better then without. I smell enough stinky fumes working on brown trucks every night. I deleted the muffler and kept the cat and it sounds good to me.

DodgemnLeavem

YUPPERS thats what I did I just left the cat on no Muff, I like the sound I did notice a little big more and It did improve the Mpg's Diesels are exempt here but too was wondering what the actuall numbers were from removing it versus
keeping it.

AH64ID

I have removed both and there is no mpg gain for me, not even a seat of the pants change.. But I like the kitty gone for 2 reasons.. 1, it smells like a diesel again and 2 is I think the extra smoke from my Smarty Jr would have plugged it and caused issues.

I have read people dyno with and without and if the cat is in good working order it only costs around 2hp.

rockcrawler304

Well put. This is the reason I took off the muffler for a straight pipe and left the kitty there. Money for mods is better than money for fines any day!!

There was a video floating around here quite a while back of a 3rd gen on the dyno putting down right at 700HP through a full stock exhaust.

Nate-03 D

I had no idea so many people had cats on their trucks on this forum. I thought only the CA trucks came with the cats?

Anyways, I removed mine. Was it beneficial? I dunno, did I gain anything by removing it? I dunno either. I do know that I might have gained a mile or two just by the weight savings.

AH64ID

Just be glad you have a late 03.. Cuz if it had a cat in 03 then it was a CA truck, and most CA 03's had 47RE's.

Nate-03 D

No I have a early 03. Build date of 03/03. It's a CA SO. Came with a cat and I lucked out and got the 48re.

AH64ID

An 03/03 would be a mid-late 03. Anything after the 1st of the year is generally a late 03. My 05 is an early 05, build date of 10/04. I think the next model year starts coming out in what July/Aug usually?

But yes you're lucky.

gadget

For what it's worth, I put mine back on yesterday. I ran around with a Genos muffler delete and an MBRP cat delete for about three months and saw a 0 mpg increase. Admittedly, it was fun for a while, but at 71/72 mph and above the drone was pretty obnoxious. With it back in, my egts are ~25-50 degrees higher when cruising and they take a noticeably longer time to cool off, but certainly nothing to be concerned with.

Truck sounds fine with the cat, sans muffler and I do feel a little bit better knowing that I'm not polluting as much and not having to worry about any crazy DOT/EPA checkpoints... and my neighbors might even thank me.

That said, anybody interested in the MBRP delete pipe?

sid325

Yeah, I just put mine back on as well. Things are getting stupid in Kali. I had mine cut and spliced to accommodate my 5 inch exhaust. I can't say I noticed any increase in egt's or cool down time. I never saw an increase in MPG. The only downside so far is the crappy chemical smell of the exhaust again.

tslewisz

No drone w/ my kitty and no muff. It's louder, but not in the cab pulling - NO DRONE. I find myself lowering the passenger side windows to listen to the sound off of building/walls/whatever. The $ I spent on the Aeroturbine, which split, was a total waste. Finally got around to putting on the curb tonight. 800 block of Douglas St in Bloomington if you want it. :-)

AH64ID

You're lucky.. The drone with towing when I had that setup was unbearable.

tslewisz

I was really surprised, actually. Weird, huh.