Before I had my engine mods, the lowest I had was 19 in all city. Same engine (sedan). So something must be wrong.. I would pull 19 with WOT at least once or twice every drive.
What have you checked so far?
CRABS o3, Custom Magnaflow Exhaust, WAMS Performance tune, Racingline STB
Platinum Apex Rims (18x8), Hankook v2 215/45R18, Painted calipers (Red), Complete debadge , Handle Overlays (Gloss Black), Arrow Overlays (Gloss Black), Grille Lighting (White LED's), Tinted Tails (2 coats VHT Niteshades), Painted Battery Cover (Silver with Red), Painted Engine Cover (Silver with Red), Eagle Eyes Projector Headlights (Black Housing), Upper Recessed Grilles (Chrome)
2 12" Memphis Subs (15-MCP12S4)
600watt Sony X-plod Amp