Code 21
Problem with O2 Sensor feedback circuit. Occurs if engine temperature is above 170°F (77°C), engine speed is above 2000 RPM, but O2 sensor stays rich or lean (no signal) for more than 22 seconds.
Problem with O2 Sensor feedback circuit. Occurs if engine temperature is above 170°F (77°C), engine speed is above 2000 RPM, but O2 sensor stays rich or lean (no signal) for more than 22 seconds.