4" Turbo Back Cat?

[Moorya52]

So I plan on doing a few mods to the truck in the spring. So far I have tried to be pro-active and changed to ELC Cat coolant, Installed a coolant filter, Scan-gauge, and did the blue spring update. My Delta is about 9-11 at the highest with the stock egr cooler. I live in Mass and have inspections every year. Will I lose a ton of performance having a MBRP 4"turbo back with a cat? Or should I do a SCT programmer with a light tune / egt probe? Also I still have a Ford ESP so should I not touch anything till that's done around 100k? Thanks

06 F350 6.0 73k

[Hotrod_TA]

I purchased a 4" Diamond Eye kit without the cat or muffler (straight pipe) and welded the cat back into the system after opening up the inlet and outlet of the cat to the new 4" diameter. Works well and only took a few minutes extra to stay legal without going all the way back down to the stock sized piping. I did run with it straight piped first and noticed a few degree rise in EGT after reinstalling the cat, but not enough to make me worry yet.

One thing I am considering doing is making a drop out section with two of the 4" band clamps to allow me to easily swap between kitty and no kitty... I have an extra section of 4" exhaust pipe to try it with, so I might as well...

[Karls03]

Read your ESP closely, it says 5 years OR 100,000 miles, being as this is 2012, you've covered the 5 yr mark.