My 03 gt must be female. Had her for 2 years now great car w 170,000 on her. She feels fast as crap one day and weak the next. More than not weak. As in one day she's s blast putting you in the seat even in 3rd and the next feels like I'm pulling a trailer. 3 tanks ago she ran strong thru the whole tank but these last 2 back to being slow. And it's s pretty noticeable difference in power. Always runs smooth, just when you floor it some days are way better. 5 spd btw. No codes. Always run bp 87 gas. Only mods are or x pipe super 40, kn filter and nitto 555 275s. Tune up not long ago, everythings great on car. Maybe I just need a good tune? What could cause this and not throw codes? I just wish this thing would run good all the time!