My car has been missing when you give it too much gas. I took it and got it scanned for codes etc... and i found out that it is the opti. How do i know if i need to replace the whole thing or just the cap and rotor?

 

The Opti only sets two codes - DTC 16 and DTC 36 - and both of those are for the optical sensor. There are no codes directly related to the high voltage side (cap/rotor). Which code did you get? They can also be set by a corroded harness connector.