What is the check engine light and what does it do?
Brad Schaefer of Schaefers Service Center Inc in Slinger, WI explains.

What to do if the check engine light comes on?
John D. Haufelder of Jerry's Automotive Service Inc. in Waukesha, WI explains.

What is readiness and what do I need to do?
Brad Schaefer of Schaefers Service Center Inc in Slinger, WI explains.