I have a 2006 6.0 and am thinking about deleting the cat. There's a 4" MBPR cat-back system on there now but every thing before that is stock. I was planning on putting a bigger downpipe on later also. The EGT's aren't monitored by anything, but i assume they will go down. True? What about mileage? Will deleting the cat cause any issues now and in the future? What is your experience with doing this? Are there backpressure issues or any thing like that? Will this make the engine light come on? Honestly, the main reason for doing this is so it will sound better. But, i don't want it to be obnoxiously loud like some dodges. Thanks for your response.

 

Ok i have the exact same exaust i just deleted the cat and muffler and my truck now sounds like a 747 taking off. A cat delete is illegal in my state due to emissions but i havent been caught yet. It was well worth deleting the cat and muffler. I couldnt even see through my cat and i have an 06 6.0 with 40k on it. I havent had any issues with this on my truck

 

thanks for the info. i've heard another 6.0 sounding like a jet when it gets going. i assumed he didn't have much of an exhaust and that i was hearing the turbo through the exhaust. we don't have emissions testing in texas when it comes to diesels. they don't hook the computer up to it. it's just a safety inspection. so i'm clear on that part. i might just delete the cat and see how that sounds then go from there. has it done any thing to your mileage that you notice? thanks again.

 

I have been at a steady 19 mpg. Ever since deleting the cat ive gained 1 mpg and and more power due to the cat been soo clogged. But i also have a hypertech max energy that has been giving me alot more hp and gas milege. Whe. I bought this truck i cod only get 13.8 mpg and now since i have a 4 inch straight pipe and a hypertech im at 19 mpg

 

i've got the max energy too. currently i'm getting around 13 in the city and about 18-19 on the highway on long trips.