New exhaust

[jwduke]

My 04.5 needs new exhaust... can I put on a system for a '04 WITHOUT the catalytic converter? Any advantages of going with out a cat? Thanks!

 

[DNDracing]

Not sure on the '04 system, but I put a turbo back on my 2005 and got rid of the CAT and I've had no issues. I did see a small drop in my EGT's with the new system.

 

[jwduke]

Diod you see any increase in power or mpg's?

 

[jgillott]

If I remember correctly, the general idea around here has been that there is no real power/mpg advantage in removing the cat on a stock or near stock truck.

 

[DNDracing]

No change in either. Sounded better (my wife may argue with that), that was about the only change.

 

[p-Bar]

I kept the Cat and ditched the muff

 

[jgillott]

I kept the Cat and ditched the muff

I kept the cat on both of ours. We have an MBRP system on the 04.5 and a Silverline on the '07. Both in 304 stainless. Well worth the money around here with the road salt.

 

[EDankievitch]

There's a rumor that the guts "fall out" of the Cat when a Cat back system is installed... I can't say for sure but my old 05 got much louder after the Banks kit was on it... Had a deep hollow empty sound...LOl. State emmissions inspection guy never looked inside the Cat, just needed to "see it in place". But I have no idea what could have happened to it.....LOl

 

[JJPage]

The downpipe from the 04 system will not match up to the cast elbow on your truck, so you have to use or specify a full 4" downpipe when ordering. The aftermarket companies will understand what you are trying to accomplish if you want to eliminate the cat, and will set you up with the right system. Not sure of any performance increase, but the sound improvement will be noticeable.

 

[Joseph Donnelly]

I have a couple 4" downpipes that are swaged to fit the early 03-04 elbow, and a spare 03 type elbow as well.

 

[Dreamer]

I went with the MBRP stainless turbo back system. I Eliminated the cat and hated the sound. Maybe if you like the "look at me" sound it may be OK but for me it was way too much noise. I ended up adding another muffler (quiet tone from MBRP) at my expense. Not happy they did not offer that muffler as a "system" but I only found out about it after complaining about the obnoxious noise. The first system was way too much drone and noise for me but now it's acceptable with the extra muffler

 

[p-Bar]

I went with the MBRP stainless turbo back system. I Eliminated the cat and hated the sound. Maybe if you like the "look at me" sound it may be OK but for me it was way too much noise. I ended up adding another muffler (quiet tone from MBRP) at my expense. Not happy they did not offer that muffler as a "system" but I only found out about it after complaining about the obnoxious noise. The first system was way too much drone and noise for me but now it's acceptable with the extra muffler

Ya the CAT seems to muffle just enough for me

 

[Jim Ross]

I had a 4" system on my '01 with no muffler (no factory cat) and I have a 4" system on my early '04 with no muffler (no factory cat). Both are pretty loud, but sound like a truck should sound. I did not notice any increase in mpg or hp, but both trucks cooled down faster with the 4" systems and the egt when towing was several degrees less than with the oem exhaust system.

 

[Bob4x4]

I ran without the cat for a couple months while I had it loaned out for a "project"
I prefer the sound with Cat.Admitedly I am no spring chicken but in my testing at the 400hp level 4hp difference-small enough to be just a dyno

 

[Scottyg1]

Call Wally at FTE Diesel. Google and it will come up. Talk to him and he'll answer all your questions. I installed a 5" turbo back system with his 30" resonator/muffer couldn't be happier. Sound is almost stock, so if you're looking for loud you can just use the muffler delete section that comes with Wally's system or talk to him about another muffler. Delivery was fast, order complete. His system uses the good band clamps. No cutting easy install.

 

[JJPage]

His system uses the good band clamps.

This is very important, make sure to spend the dollars for the SS Band Clamps, you will not be sorry!

 

[DNDracing]

2nd the band clamp tip. The MBRP kit I bought had the cheap u-bolt clamps. I spent the $$$$ and upgraded to the SS clamps.