jvmagic

Hi, My is250 has 110k miles and I've haven't performed a spark plug replacement etc (just basic maintenance throughout the years). The CEL came on yesterday with the P0303 code and the car ran real rough. After reading the code, I reset the computer via my handheld scanner. It's ran fine and no CEL after driving 10-15 minutes. Not sure if I should risk driving further. Any advice would greatly be appreciated. Thanks in advance