I've searched around and not found a ton of concrete info on this:


I want to add a 4" exhaust to help out with any EGT issues, from what I have read Turbo back is the way to go. Issue is I need to pass emissions in CO still so will need a cat. (I'm assuming)


What exhaust system do you guys suggest? Also what about a cat? If I go to 4" I will likely need to upgrade/change the cat out too correct? Do I need to go to a higher flow cat? Can I use the same one that's on there and just adapt the inlet and outlet to the new 4" pipe?


Thanks for any info!

 

Whatta ya got?

 

Crap sorry forgot I didn't add that to my signature yet. Guess that's need to know info LOL


'03 Excursion 6.0L Limited.

 

Don't know about the 6.0, but my 7.3 is already cat-less. Maybe some 6.0 guys can chime in. I upgraded to 4" a couple of months ago, I expect no problems passing emissions.

 

Usually if it has a cat, it'll have to keep a cat on there. It's a federal law.

But a lot of people take them off....

 

High performance cat's, while expensive, are available. I don't understand why people choose to opt out and usually find a 'hook up' that charges under the table to 'pass'. That hook up charge would've covered the cat after a few years and kept things legal.

We, as well as many other shops, have done extensive testing on hi-flo cats over hollowed or deleted ones. The difference is power was so minimal it's not worth the risk - 5-10hp, and that was on pretty rowdy street legal motors pushing 650-750rwhp.

As a disclaimer, those tests were primarily performed on GAS motors, with four diesels in the mix.

 

I commented on an earlier post that I was going to get a diamond eye 3.5" down pipe and use stock hollowed out cat and then 4" flo pro cat back. After shopping around it looks like the best price is going to be the diamond eye turbo back that utilizes the stock cat and has the 3.5" dp. You can get it with or without a muffler. With their muffler it can be had for around $260. They also offer a cat delete pipe for the stock system for around $50 and just swap the cat in when needed for testing. If you aren't interested in the 03 turbo whistle you may want to keep the cat!

 

I saw your post earlier which is why my post was spawned LOL. I'm new to diesels so I didn't want to mess soemthing up.

You are looking at something like this?

K4352A Diamond Eye Exhaust

plus

Diamond Eye 125030 Ford F-250/F-350 2003-2007 Diesel 6.0 Powerstroke | 3.5" Downpipe Section 1

Or if you have a link you can set me up with for the whole kit that would be awesome!

Thanks for all the feedback from all of you I appreciate it!

 

My google fu shows me this one - Diamond Eye | K4352A | 4" Turbo-Back Single AL: 2003-2006 Ford 6.0L Powerstroke Excursion not sure what down pipe it has as the "comes with" description is a little lacking

 

Just to clarify..my 7.3 is cat-less from Ford. Do 6.0's come with a cat standard?

 

yes

some 7.3 were Non- Catalyst equipped and do not require a cat converter to pass even CA smog, but in CA if your diesel truck came equipped with a cat then only the factory cat will pass smog inspection, and they are upwards of $1200 bucks

 

http://m.ebay.com/itm/Diamond-Eye-4-Aluminize-TurboBack-Exhaust-03-07-Ford-Excursion-6-0L-Powerstroke-/281943174162?nav=SEARCH
http://m.ebay.com/itm/Diamond-Eye-125034-Oem-Off-road-Pipe-3-5-Aluminized-2003-2007-Ford-6-0L-/311380559391?nav=SEARCH

 

So, in the northern California state of Washington, emission standards are the same as in California. I have always passed using a 4" Cat back system with a Donaldson BTM. The factory cat is still there, well, the shell anyway, and again, it always passes. This suggests the cat on these, federally required or not, adds absolutely no value, emissions wise. Of course, the vehicle is only driven off-road....

 

How does the donaldson BTM sound. We had the 3.5" installed on our 7.3 without cat and sounded great with no drone.

 

I love it. Not loud, but you know there is some power there. Since the cat work there is a whine, but I like it!