I am trying to get my car ready for tracking and it started acting weird at the end of last season. When I shift, especially near redline and under full accel, the revs actually go up briefly when I would shift, like I was pressing the clutch in before I got off the throttle, which I was not doing.

Upon checking the CEL codes, I am getting the following:

P0455 Evaporative Emissions Control System Pressure Sensor Leak Detected (I think)

P0507 Idle Air Control System RPM Higher Than Expected (I think)

P1145 Cat problem (don't remember the exact code)

Any suggestions? Does this story all fit together or what? I know the P1145 is a cat issue but the other codes are new.