P0121 Chevrolet -malibu

Question

My engine light came on yesterday had it read and the code p0121 came up on the scan later that day engine light came off. This afternoon it can back on when I started my car but it was a hesitation in the ignition then went back off.

Answer 1

P0121 Throttle position sensor circuit range / performance problem

This is exacly what a intermittent TPS sensor does. Which is part of the throttle body assembly.If the code return with a P0121 you will need the TPS.