Chery OBD Trouble Code 21

O2S Stays at center
O2S shorted to voltage
O2 sensor does not detect rich or lean condition, or O2 sensor input voltage too high. DRB will indicate which side with dual sensors. The O2 senso

Oxygen sensor circuit

Oxygen sensor reporting too lean or too rich after 2 – 12 minutes with temp over 170° and RPM above 1500

Main oxygen sensor signal fault

Neither rich nor lean condition detected from the oxygen sensor