I have the same car, but mine is an 07.
My exhaust:
-DC Sports Ceramic 4-2-1 Header w/ Heat Shield Delete
-Stainless Steel Flex Bellow (Flex Pipe Delete)
-Magnaflow Catalytic Converter
-Vibrant Performance Stealth Muffler
-Resonator Delete
My engine:
-OBX Racing Intake Gasket
-Unorthodox Racing Underdrive Pulley set
-Gates K070694 Belt
-Apexii Neo A/F Computer
-K/N Short Ram Intake w/ Heat Shield
-Acura TSX Intake Manifold
-P2R Thermal Gaskets x3
-P2R Fuel Rail w/ Harness Tuck
-P2R Throttle Body Spacer
-Spoon Sports 1.3 Bar Radiator Cap
-NGK Iridium Sparks Plugs
Can't supercharge or turbo b/c the ecus are locked up. Not much else to do to those motors. Don't dig internally. Swap a tsx engine if you want to be properly quick, or a j series