Home Forums Gear Hunting Trucks and Four-Wheel Drives Catalytic converters and diesels

Don't want to hijack the previous thread, but driving back from Colorado earlier this week, the wife and I decided that we probably would be happiest if we just went ahead and bought another 3/4 ton diesel pickup. She was asking me if the new diesels have cat converters.

I did a cursory search earlier this afternoon, but could not find a straight answer. So, I am asking those of you who hang out on this side of the 'Fire, what's the scoop?

Thanks!

Yea, I think they all do nowadays. I have a 99 dodge diesel with no cat, the 98's had them but when they changed to the 24 valve in 99 they didn't need them for the emissions. Dodge didn't put cats back on until 2004.5 if I remember right when they had to have them for the stricter emissions standards. The emissions have been tightened so much now that I'm sure they all require cats to meet them.

Yes they all have them now, pretty easy to get a cat delete or even a full DPF delete if you'd like.

99% of what I've read on the various Dodge Cummins forums, people only might pick up about a 1/2 mpg deleting them (Cats that is).

not only the CAT , they got EGR , DPF (particulate filter ) , and the Fords and Chevies also burn urea , along with diesel fuel .

Thanks, Guys!

Mine doesn't, but it is an 03 f250 7.3l 4x4 with a manual. I would love to tell you if it ever had one, but the first thing I did after buying the truck was put on a 4" exhaust. Well, actually I drove it from west Texas to Ohio, but I had the exhaust waiting here for me.

Don't know what you guys are talking about. I had to have my '06 Dodge "pass" a smog check. The guy doing it said their was no standard or smog gear on my truck. Now I do understnd that the '07' and later Fords and Chevys have urea injection, to promote a cleaner burn. So far, the Dodge doesn't require it. E

Don't know about a cat, but they have a DPF and the Ford and Chevy have DEF (urea) as well. Mileage is still good and stock power is way up over previous years, so they must be doing something right. They are quiet and the exhaust is cleaner than a gasser. Other than the sticker price, it's a no brainer.

Yes and no. Yes they have them But the CAT on a diesel isn't like the a converter on a gas engine, it's really a soot collector. Chevy started having them with the '04.5 LLY engine. In '08 when ULS fuel and the much tighter emissions went into effect, diesels also added DPF. All the late model diesels have some kind of stuff like that and it all hurts fuel mileage. A friend changed his 09 or '10 Dodge around and took off at least 100lbs of piping and crap. Chevy's have a urea system. Lots of people have complained, but about 1/2 the European passenger cars are diesel and they've been using that system for years so it must work. Still, the emissions crap makes pre-'08 diesel trucks far more attractive.

Go to a dealer service dept. and ask about emissions stuff.

Up until early '07 Dodges didn't have all the extra crap, I believe '05-early '07 do have a Cat though. My early '07 5.9 does.





Believe '12 Dodges will have Urea.... Thanks (up yours) EPA

All this crap they require for emissions costs fuel mileage, so consequently you use more fuel which uses more natural resources and I'm guessing it's safe to assume pollutes more if you/we actually got better mileage. Plus you can get more diesel out of a barrel of crude than you can gasoline, so rather than promote diesel engines in the US they try their damnest to keep them out.

Catalytic converters were put on all dodge diesels made after 2004.5 models. If yours doesn't have one then it was taken off, it came with one from the factory. I'd imagine that the guy doing the smog check didn't know what he was talking about.

My '97 had a cat. It was lost a few years back. Much better performance and easily meets emissions.

Its called SCR (Selective catalytic reduction) and that system uses DEF (diesel exhaust fluid) or "urea". Other than the pain of adding urea every now and then I like it. Cummins will be switching to it or so they have said.

Pros of the system NO EGR!
Exhaust Gas Recirculation is dirty and creates heat that is unwanted. Why would you dump dirty air into your engine if you don't have to?

The urea, or diesel exhaust fluid (DEF) is injected into the exhaust stream, NOT into the engine.

The urea reacts with oxides of nitrogen (NOx) to form ammonia (NH3). Then it encounters a catalyst in the selective catalytic reduction (SCR) system and is converted to nitrogen gas (N2) and water.
I believe model year 2011 was the first to use this.

True story it is added to a tank under the hood (GM Trucks). I did mean to make it sound like you add it to the engine, sorry about that.

It wasn't your post that prompted the explanation, but rather the idea that urea is injected for a cleaner burn. It was for those unfamiliar with the technology.

FWIW, In the Fords, the DEF fill is inside the fuel cover next to the fuel port.

Thats a better place for it if you ask me.