Code 21
Problem with O2 Sensor feedback circuit. Occurs if engine temperature is above 170°F (77°C), engine speed is above 1500 RPM, but O2 sensor stays rich or lean for more than 60 seconds.
Problem with O2 Sensor feedback circuit. Occurs if engine temperature is above 170°F (77°C), engine speed is above 1500 RPM, but O2 sensor stays rich or lean for more than 60 seconds.