Pedal Position Code on 2005

Please specify the exact code. In the meantime, I assume the code was either P012x, P022x, or P2135 (where x is some number from 0 to 3). In all of those cases, the throttle position sensor is the most likely suspect and needs to be replaced.

The sensor is made of two variable resistors which track the throttle plate opening angle. When one of the variable resistors starts to produce a faulty reading, the engine ECU will generate the DTC.

Assuming that the logged code was one or more of the ones I listed, you need to have the throttle position sensor replaced now. If you allow the condition to continue and the sensor gets worse, the throttle angle will be locked open at only 16 degrees ("limp home" mode) and the engine will perform very poorly.

If the car was previously subject to a front-end collision then the wiring harness associated with the throttle position sensor needs to be checked for integrity.

If you take your car to a Toyota dealer for service they may require that the entire throttle body assembly be replaced which likely will result in a four-digit charge. The repair manual does not provide a procedure to separately replace the throttle position sensor.

Hence, you might look into the availability of a used part from a salvaged vehicle. The throttle body assembly can be replaced fairly easily as a DIY project assuming you have the correct tools. Replace the gasket between the throttle body and the intake manifold with a new part. You cannot allow any air leaks below the throttle plate.

 

DTC P1121 means the engine coolant flow control valve is failing. That is a totally different issue than the throttle position sensor.

The urgency to replace that valve is not so high, but it's failure may impair cabin heater operation.