I am running ASM LT's on my ECSB with the stock y-pipe, but magnaflow high flow cats. Been thinking about having an extra Off-Road Y-Pipe fabbed up next month after my inspection is done, all flanged so I can swap the catted y-pipe back in when inspection time comes around. My rear 02's are already turned off.

I know it will increase sound volume quite a bit, which I am wanting, but as far as performance, any real gains to be had with the ORY versus a catted setup? Keep in mind, I am mostly stock at this time, but will be getting a cam hopefully by this coming Christmas season.

 

more noise, more stinky, more raspy, more . . . clickity clak clak and wha a hwa wahhhh

 

5-10 horsepower isn't out of the question...

 

mine dosent smell too bad, i am on the stock cam though get one fabbed up IMO. with the right muffler choice there will be no rasp.

 

Not sure about your original question, but did you get any gains or sound changes from the Magnaflow cats?

 

Well, I did the magnaflow cats with my long tube header install so I can't really say for sure. I had the same setup as far as headers with my 5.4 crew cab, but stock cats and the magnaflows definitely seem louder that the stock cats. I noticed a big low end gain too going from the true duals back to a single 3" exhaust.

 

Youll lose some low-end.