So I got this done for a total of $350 at my local exhaust shop. Install and parts.
What I did was remove the giant two cat system and replace it for the flowmaster hi flow 2.5" in/out cat, and had him put the o2 sensor as close to the cat as possible. Then he ran 2.5" pipe to the muffler which is a flowmaster 40.
I have no cel after 500 miles and it sounds awesome, throaty and crisp.
No longer mumbled by those stock cats.
Power feels about the same, gas mileage went down an mpg or two but it's definitely worth it.
Just posted this thread but figured id let you know here too haha