ok I am going to put an exhaust on my truck. My exhaust guy wanted me to check on something as he has run into this problem. Im not sure if those customers had this problem because they did a 5" down pipe and exhaust or not but... He said customer lost ALOT of power until they welded the cats back in. now these are GMC 2500's he hasnt done a 6.0L Ford yet so he wanted me to do some research.

I like the sound of the MBRP exhaust. Any others that sound like it?

I want to do a turbo back, so I am planning a 4" down pipe and 4" back with 5" tip. do the kits come with the provisions for the cat or will he have to cut and weld the cat back into place? Will I even need the cat in your opinions? Did those other guys lose power because they did 5" BESIDES them being GM? I had to throw that in there... Please fire away with your input. Thanks

 

Get rid of the cat. And I don't think you can fit a 5" down pipe in there... My 7.3 is running a 4" down pipe with a 5" exhaust. No cat, no muffler, to a 6" tip. Sounds amazing. Didn't seem to notice any low end loss. Makes more boost and spools up quicker too.

 

Zman, are you aware of the emission laws in MA?

tlap, how about you?

Check into it before you remove the catalytic converter/s.

Make sure your exhaust guy understands the consequences.

 

Nope, not at all. But with all of the mix of diesel trucks coming with or without a cat, he won't have a problem passing a visual test. And diesel trucks passing an emissions test? Come on.

 

He/you may need to be acquainted then.

http://www.dmv.org/ma-massachusetts/smog-check.php

 

That article said nothing about the cats and/or a diesel motor.

 

Yeah, yeah, this doesn't specifically say anything about "catalytic converters" either, but the OP may want to research more before following your advise.

Carry on.



http://www.mass.gov/rmv/regs/lev.htm

 

In the world of diesel trucks, very, very, very few run cats. Half the trucks didn't come with them, mine didn't. And a 5" downpipe? Thats ridiculous. Theres no need for anything more than a 3.5" or 4" downpipe with 4" from there back. Even 5" downpipe-back is overkill for a mostly sock truck, IMO.

 

I prefer dogs over cats!

Of course when it comes to the human kind - vice versa!!

 

Methinks you need to do some more investigating in the world of diesels. The 7.3L was indeed spotty when determining if a cat was installed factory or not. The 6.0L is another story as its Tier III emissions compliant requiring a cat. The 6.4L which is Tier IV compliant most definetly has one. The OP has a 6.0L so he's guaranteed he's got a cat. BTW, the laws pertaning to cats is federally mandated, so if it came with one it must keep it until it reaches a certain age then it may be removed. Chances are it will probably slip by without getting looked at, but if it does it carries some pretty hefty fines.

I would suggest you simply get a cat back system since there isn't going to be huge gains in going turbo back on that truck over the cat back.

 

On a 6.0l it has been proven that putting the CAT back on has actually had mileage go back up a little. We had one of our cutomers call us and tell this had happen to him. He was netting 21mpg in the 80hp econo before removing the CAT. He removed it and it dropped to 17. The tech could always remove it so it an be eaisly put back on later. Jody did this to my old 05 6.0l and the owner now had the CAT put back on to test this theory.

I am just a sucker for the turbo back systems.

Diane

 

Hey lookie there... A real tuner. Glad to see you found the site Diane.

 

LOL, I am definately not the tuner. I did take a gas tuning class 2 years ago, but I have so many other duties in our business I could not find the time to play. I like to race them and leave everything else to Jody.

 

Hey, whatever works. I (and a few others) have mentioned your name a time or ten on here...

 

Thank you. We are looking forward to being here.