2004.5 Catalytic Converter

[Sixpac2]

Hi,

I have a 2004. 5 and was reading some old magazines?

Came across the differances from and 03-04 nad the 04. 5-07.



It talks about the Diesel oxidation catalyst. (catalytic converter)



I have 99K and tow a large 5ver most of the time. As I get more miles on the truck is there anything to watch out for or do as far as the exahust system is concerned.



Can the converter plug up? Create excess back pressure ect.



I don't recall seeing any other TDR articles on this.



Thanks, Marvin

 

[RBellah]

Several vendors sell the test pipe which installs and takes place of the converter for the said purpose of testing. You might give this a try and see what results you get and go from there. Also, I ran across the diamond eye down pipe with resonator that would be a consideration if you do not want noise in the cab etc. Read the fine print and make sure you know the laws in your area.

Power Products Unlimited - Diamond Eye "Quiet Tone" Resonated Down Pipe 2004. 5-07 5. 9L Dodge Cummins 222051

 

[cerberusiam]

Can the converter plug up? Create excess back pressure ect.

Yes it can, but, when it does you WILL know something is wrong. Severe poer drop, engine overheating, excessive black smoke, really bad fuel mileage.



The CAT on these diesel is not really one. Its more of soot trap and burning mechanism than anything. The only catalyzing it does it finish the burn process that is incomplete in most modern diesels for emissions reasons.



As long as you are using the truck as expected and keeping the EGT's relaistic, you should have no problem with the CAT as the exhaust heat will burn any accumulations of soot.



Where problems will occur with them is excessive EGT's. The CAT is relatively free flowing but it is a honeycomg material. Apply enough extreme heat and it will melt therby restricting flow. Considering the melting temp is about 1600 degrees and the CAT is waaayyyy down the exhaust system, well, imagine the EGT's needed at the manifold to effect the CAT.



The other potential for CAT damage is an injector over fueling and letting too much fuel into the exhaust track. However, you will notice other serious problems long before the CAT has issues.



Any damaged CAT's I have seen to date are the result not the source of engine failures, no matter how hard the owner wished the reverse was true.

 

[macdaddy]

Simply remove it my using a saws all. Then remove the contents. Then reinstall.



I did this to my 05 by using a piece of rebar. Once you get a little bit going the rest is easy to remove by simply banging it on the ground.



I noticed HUGE changes in throttle response, and the amount of time it takes for the T stat to open in the morning. This tells me it is very restrictive. And when you see it you will too.



Mac

 

[Lordsman]

RBella: Will this pipe eliminate the drone I get when pulling a grade? The noise is deafening!

 

[macdaddy]

I run a gutted cat with a silverline muffler. If your straight piped with a test pipe you will get offensive DRONE!!!



Been there done that.



No drone!!



Mac

 

[BIGNASTY]

Just take it to a muff shop and have them add header flanges to each side of the cut off cat and the replacement pipe. Dont have to worry about it anymore Calif was the reason for the install and removal idea just for smog checks

 

[RBellah]

The downpipe with Resonator (NO CAT) is suppose to lessen the drone, I am thinking of running one myself... I was hoping someone eles on here had tried it.

 

[AH64ID]

When in good operating order the cat really only effects the time to cool down at idle, the rest of the time it has minimal impact, 2-4 rwhp is the accepted loss due to the cat.

Most do delete it thou as it can easily plug with more than stock fueling and soot loading that comes with tuners/injectors/etc if you just drive light around town and never get sustained EGT's with towing or highway driving.

Like it has been said if its bad you will know it, remove it at your own will if you want.

 

[MChrist]

AH64ID, I've noticed that my exhaust pipe temperatures are right around 250 degrees (measured with infrared thermometer) right after my converter, taken right after a drive. Do you or anybody else know if that is too low? On a gasser, the temp is supposed to be about 200 degrees hotter than pre converter temp. Would that imply my converter is coated and not operating properly? It doesn't smell like a truck that has no converter, though.

Any thoughts? Also, my pipe is wrapped with header wrap right up to the converter, so I can't get an accurate temp before the converter.

 

[AH64ID]

I honestly couldn't tell you. My cat is long gone.

 

[cerberusiam]

Trying to determine if this type CAT on a diesel is working by measuring external temp of the pipe, or even the CAT itself, is an excercise in futility. It is simply meaningless to how they function.



To begin with they are not even a catalytic conveter as they do no conversion. It's primary function on the 5. 9 is to trap and finish combusting unburned fuel to cut the particulate emissions. Thats is all. They do nothing for NOX and do not need the sustained temps a true CAT would need to work properly.



IRC, a temp in the exhaust flow of 600-650 degrees is adequate for the particulate burner to function correctly. That is pretty easy to get to in all but the most minimal driving scenarios. Normal use will see that, a 5 minute drive and thats all it does could possibly cause soot loading but as long as the temp gets to what is needed at some point it will clean. Since the exhaust is flowing and the temp not even across the flow all you see is the external edges and the amount of heat actually radiated by the pipe. It could be 250 is fine or totally meaningless. There is just no hard correlation to say one way or another.



The only way these things really get killed is excessive EGT's from heavy fueling that melts the catalyst and plugs the flow capability.

 

[MChrist]

Thanks, Cerb and AH. My truck runs just fine with the converter still on, and I would choose to keep it on since it kills the diesel exhaust smell once it warms up. My EGTs never get high, my boost comes on quick, and I like my exhaust quiet.
I guess I was just thinking that since converters on gassers get really hot after the converter, that diesel converters would, also. Apparently not??

Also, I ran my Smarty on SW 7 all year and was playing around making smoke. Judging by the 15 foot black anaconda that poured out of my exhaust pipe when I stabbed the throttle at idle, I can only imagine what the converter looked like!! I can't say I noticed anything different, performance-wise. And as far as being a restriction, that thing is huge, so the surface area has to be at least 4 times the cross section of a 4" pipe. I would also think that there would be some sound reducing qualities inherent in the converter design (if you are interested in quiet, that is!)

So I guess I'll just keep it on...

 

[AH64ID]

I ditched mine because I felt that added exhaust flow and soot from the Smarty Jr weren't good for it in the long run, that and the decreased EGT's of the Smarty Jr won't let it burn off as easily.

 

[Regcabguy]

I ditched mine because I felt that added exhaust flow and soot from the Smarty Jr weren't good for it in the long run, that and the decreased EGT's of the Smarty Jr won't let it burn off as easily.

Excellent point John! I recently removed my Smarty for an emissions test. This is the 4th time I've uninstalled it,but the first time for emission testing. Each time I remove it,it takes several runs at 2500-3000 rpms at full operating temps to clear out the soot. I've got maybe 100 miles on it now and it's super clean throughout the rpm range. Without Smarty,I use much more throttle and rpm's to get the power. Egt's are about 150* hotter without Smarty.



With my Smarty installed,I rarely exceed 2200 rpm because of the low end fueling. The truck doesn't have to work hard enough around here to generate high enough egt's to burn off the soot.



KO1 reflash manana,then smog. :{

 

[MChrist]

I ditched mine because I felt that added exhaust flow and soot from the Smarty Jr weren't good for it in the long run, that and the decreased EGT's of the Smarty Jr won't let it burn off as easily.

That's why I wrapped the pipe with header wrap from turbo to converter. I figured it must help.

There is usually a 200-300 degree temperature drop from just before the turbo to just after the turbo. . so I wonder what the temp drop between turbo and a thin 4" pipe that is 4-5 feet long!! Add to that the fact that I have two turbos, and that must be cooler, still. I know that I just went for a 0-100 rip, pulled into my driveway, left truck idling and shot a quick, infrared temp off the exhaust tip, and it ranged between 190-220, depending where I shot the temp.

 

[AH64ID]

Mine is wrapped from the exhaust brake to where the cat used to be for a different reason, keep that heat off the trans!

 

[MChrist]

Mine is wrapped from the exhaust brake to where the cat used to be for a different reason, keep that heat off the trans!

Huh! I didn't think about that!! I have extra wrap, maybe I'll double wrap the pipe and add enough to get heat away from trans in Spring.

 

[bsesby]

Whats a CAT? Okay joking. Its that thing that is sitting in the corner of my shop.

04. 5 4x4 6spd I get 2mpg better and yeah I guess its a little louder, but I did the silverline 4 in and would do it again. The bast part is turbo lag is way less!