P0121: Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance

What does P0121 mean?

The TPS reading does not match what the computer expects for the current airflow and engine load.

Generic OBD-II definition: Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance. Confirm applicability in your vehicle service information.

Common causes

• Worn TPS
• Dirty throttle body
• Wiring issue

Symptoms

• Hesitation
• Surging
• Reduced power mode

Can I keep driving with P0121?

Severity: Medium Drive gently and get it diagnosed soon.

If the check engine light is flashing or the car runs badly, stop driving and have it checked.

Typical fixes

• Clean throttle body
• Test TPS sweep
• Replace if erratic