UPDATE: New exhaust sounds fantastic, especially when creeping along through the city, with ever so slight acceleration... Not imposing, but a nice growl.
As an aside... After the New exhaust/manifold fix, I reset the MPG, and thus far running around 14.6 all around... Was at 12.9. I'd imagine it'll be a little lower after my normal driving patterns (mix of city and short distance country side driving, with one day of interstate use).
Also, I've been throwing a P0420 engine code for the past three years. I'd hoped the manifold fix would clear it up, although the code came up after leaving the mechanic. Not sure if these codes are automatically saved and just come on at specific intervals (was coming on about once a month for 3 days at a time and then would go away without manually clearing it), but I've cleared the code manually with my UScan unit, so we'll see if it comes back (I've had the Jeep assessed at a couple mechanics, but the root cause of the code was never truly found: one tried changing spark plugs/timing/etc, the other (current) felt that the manifold issue could be the cause, but couldn't guarantee it).
Next UPGRADE:
Just waiting on a BT catch can to arrive, at which time I'll install the AIRRAID MIT/BT catch can, a well as clean the throttle body...any recommendations for cleaning the throttle body are welcome as I've never attempted it in the past... Watched videos, but have received varying messages with regards to cleaner use/etc. It looks like removing the throttle body is best (removing the negative lead before hand), with use of CRC throttle body cleaner and a tooth brush/denture brush. My impression from videos/write-ups was that you aren't supposed to move the butterfly once it is off the vehicle due to sensor memory, which can cause trouble codes once placed back on the vehicle. As I don't own a more advanced diagnostic unit that has a "throttle body re-learn" function, I want to be careful. My understanding is that the vehicle's computer will generally re-learn without issues, unless you have trouble codes.