I am certainly ignorant here, but was not aware that diesels had catalytic converters except in Europe. Converters will be used in the U.S. to meet the 2010 EPA standards.

Diesel catalytic converters will require urea fluid sprayed into the exhaust gases. Here is some info taken from Transport Topics 8/18/08. Cummins Engines changed their plans and have switched from exhaust gas recirculation to urea-based selective catalytic reduction for 2010 engines. Cummins is now in line with Daimler, Paccar, Volvo and Mack. The switch was caused by the increasing cost of diesel fuel making fuel mileage more important. SCR engines run more efficiently. Also, the recent development of copper-zeolite for a catalyst is proving to be superior to the iron-zeolite catalyst available when Cummins ran its original SCR tests three years ago.

This leaves Navistar as the only engine manufacturer planning to use EGR. Caterpillar announced earlier that it would end heavy engine production after 2009.

A distribution system for Urea should be in place in the U.S. by 2010. So called diesel exhaust fluid or DEF is a combination of 32.5% pure urea and 67.5% highly purified water. Most over-the-road trucks will need 2% DEF for every gallon of diesel, and will have a urea tank of between 22 and 35 gallons. Smaller bottles will be available so that drivers can top off tanks between stops at pumping stations. A 2.5 gallon container more or less equivalent to the 10-liter urea containers popular in Europe and weighing about 25 pounds will be about as much as drivers will be expected to handle.

Originally Posted by jakescia

Subject came up over coffee-----too many different opinions expressed for me to believe that anyone knew for sure.........

What are the rules related to removal of catalytic convertor from Class 8 diesel built after, say, 2004??

Where might I find those rules?

Thanks.

Also depends in the state you live in, Here in TX we are still stuck in the stone age and do not have strick EPA law's yet or at least not enforced. I replaced the muffler/Cat combo on my '04' FL W/CAT with a pair of 5in. free-flow "Dynaflexes" and saw a jump in MPG's and ran alot better.

Sorry for nit-picking. I did not think of the diesel particle filter that came out in 2007 as a catalytic converter. Now, I read that it is catalyzed although it is primarily a soot and carbon particle filter.

http://74.125.95.104/search?q=cache:...lnk&cd=5&gl=us

Originally Posted by SPIKE 64

I replaced the muffler/Cat combo on my '04' FL W/CAT with a pair of 5in. free-flow "Dynaflexes" and saw a jump in MPG's and ran alot better.

Could you explain, or tell me where I might learn more about "Dynaflexes"; Thinking of replacing the factory mufflers on my '04 W900, but I want to retain a low noise level.

Originally Posted by droy

Could you explain, or tell me where I might learn more about "Dynaflexes"; Thinking of replacing the factory mufflers on my '04 W900, but I want to retain a low noise level.

You may want to get on their web-site because I think KW has one muffler under the cab. Mine were by the doors and an easier swap. And as far as the noise there is none, you still retain the muffler and no noise.

2007 and onward emissions require two things: DPF and DOC. You all know about the DPF, the second half of the canister is the DOC (Diesel Oxidizing Catalyst). It works on a similar principle as a car's catalytic converter reducing both unburned carbon emissions and NOx emissions. However it isn't enough for 2010, hence SCRs coming out.