P0121 2004 Toyota Prius -

Question

Should I replace the entire throttle body or can I get away with just replacing the sensor on its own?

Answer 1

P0121 Throttle Pedal  /  Position sensor  / switch A circuit range / perfromance problem

For this code condition the TPS are tested to ensure it is the TPS and not the ECM, This code when it occurs majority which is 98 % of the time is the TPS, which you have to replace the whole thottle body.