Possible Causes

WARNING: This page is about a different car, the 2003 Mazda B4000, 2003 Mazda B3000, and 2003 Mazda B2300. However, it is still accessible from the selected car via links, so may be relevant.

Possible causes are:

Air leak between MAF/IAT sensor and throttle body (DTC P1121).
Binding or bent throttle linkage (DTCs P0121 or P1124).
Corrosion on TP sensor, PCM or harness connectors (DTC P1120).
Damaged MAF/IAT sensor (DTC P1121).
Damaged PCM (DTCs P0122, P0123 or P1124).
Damaged TP sensor (DTCs P0121, P0122, P0123, P1121 or P1124).
Frayed wire (DTC P1120).
Intermittent open or short in TP sensor (DTC P1125).
Open SIG RTN harness circuit (DTCs P0121 or P0123).
Open TP SIG circuit or TP circuit open to PCM (DTCs P0121 or P0122).
Poor continuity through TP sensor connectors or harness (DTC P1125).
Throttle plate less than closed throttle position (DTC P1124).
Throttle plate/screw misadjusted (DTC P1124).
TP sensor loose pins (DTC P1120).
TP sensor not seated properly or tightened down (DTCs P0122, P0123, P1121 or P1124).
TP circuit short to ground (DTC P0122).
TP circuit short to power (DTC P0123).
VREF harness opens or shorts to TP sensor (DTCs P0122 or P1120).
VREF short to power (DTC P0123).
VREF short to SIG RTN (DTC P1120).