Sh0nuff

Ok guys I am 100% stock...
Want to get a downpipe...
Which one would be best?
ZZP or XTC both w/cat 2.5

Future plans for a wideband and mounts...

I am thinking my cat is fried.... so might as well do this..

Any other reasons why I can go full boost with little to no power behind it?
Exhaust note changes...have been through a few different sounds now...
No whine really.. slow to climb over 3grand...@ full boost, sometimes power will kick in on and off.
resonator makes clicking sounds even while at running temp and throughout driving.
supercharger gets very hot...and intake mani gets very hot.
heat exchanger pump is working.
Normal stuff is done...maf clean...new emissions evap purge..no vac leaks can be found, clean tb...new tb gasket..newer plugs..newer air filter..newer fuel filter.
Blah blah blah...so on and so forth...this is all I can think of.

Oh I know cat was changed by dealer at 20k...