Polo EPC Light Due to Throttle Body Contamination

Carbon buildup or mechanical obstruction within the throttle body prevents the throttle plate from achieving the precise angle requested by the ECU. Confirm this by using an OBD-II scanner to monitor the 'Throttle Position Sensor' (TPS) actual vs. target values; if the actual value fails to track with the commanded target, or if the error codes P0121, P0122, or P0221 are present, the throttle body is confirmed to be the primary cause of the performance loss.