catalytic converter?

[jandr]

Yeah I know removing it isn't leagal, just wondering if anyone has and what the noticable benefits (if any) are. I realize they would have to be on for emission checks in those states that have them. Emissions checks were the only thing that stopped us from taking them off our gassers YEARS ago. (me at least)

Man this exhaust sure stinks... ... ... ... . where's my good old diesel fumes?



Any input? +'s, -'s, codes, what states have diesel emissions checks?

 

[RBell]

When I took my off the first thing I noticed was it was much louder, and you'll have your old diesel smell back. I noticed a slight drop in EGT but nothing big just about 25 degrees. No change in mileage. I've had mine on and off a few times, with my MBRP muffler it's loud as hell. . ROB

 

[TX Gooseneck]

I had mine off for the 1st 100k (had 5" from downpipe back), put it back on, aswell as the stock system, my egt's towing went up approx. 200 degrees. With injectors and turbo, when I took it off it dropped back considerably, a bit over 200 degrees. But the noise is pretty bad, I put a magnaflow stainless on and that helped the sound out.

 

[steved]

Loud.



Mileage up a little bit, not much... maybe 0. 5 to 1. 0 mpg?



Definately runs better.



steved

 

[CPG]

The catalytic converter on my 04. 5 seems to take out the sooty smell of exhaust my old ist. gen "93" had. Yes ! I believe its more quiet too. The mileage between the two trucks seem to remain much the same.

Just my humble opinion here.

 

[jandr]

Perhaps they are engineered good enough to not really affect performance. It's just that my experience with them in the past had been that engines always seemed to run better without them. But if there's no real big advantage in removing it then I'd probably just leave it in. Has anyone had a problem or heard about a problem with them clogging or going bad? I would imagine EGT's would show a problem. They gotta cost a fortune!

 

[Dieselnerd]

I ran without on my 2nd gen. No apparent difference in mileage or power, only difference was EGT was slightly cooler, not enough cooler to make it worthwhile, around 25-50 degrees less. I removed it at around 50,000 miles and looking through it, there was no sign of any clogging. I saved it to re-install when I sold the truck.

 

[TexasCat.]

replace

I am in the process of replacing mine. I ordered the test replacement pipe. I am trying to do anything I can to help my egt problem. It should be in next week with a new intercooler. My goal is 100* to 200* decrease in temps. If it does happen to help the milage only by . 5, it will be beneficial over the long haul. I do have a 4 inch straight through glass pack behind it, I am hoping that it will take the edge off of the noise level.

 

[steved]

I do have a 4 inch straight through glass pack behind it, I am hoping that it will take the edge off of the noise level.

It doesn't.



And to add to my original post, I also noticed the truck runs more "free" than with the cat... the back pressure the cat placed on the engine sorta acted like an "exhaust brake"



I have over 65k with no cat... I won't put it back on unless I absolutely need too.



steved