Code P0450 - evap pressure sensor problem. Dealer advises replacing evap control system pressure sensor and vent control valve (at a cost of CDN$600) will have no real effect on drivability or engine.

Anyone have any experience with this code or family of codes?

Also, I now have a P1446 code which my mechanic says is undocumented in his computer.

 

Replace the pressure sensor, clear the error codes and you should be OK.

EDIT: It could also be a defective gas tank cap!