Chery A5/Lifan Junjie Oxygen Sensor S21-1205310 0258006937 Precise Air-Fuel Ratio Monitoring

Chery A5 and Lifan Journey oxygen sensor S21-1205310/0258006937 directly replace OEM parts; no re-wiring needed to install. Sensor monitors air–fuel ratio in real time and transmits signal to ECU to adjust injection; improves combustion efficiency. Fits models with the same engine; resolves high fuel consumption, muffled acceleration, strong exhaust odor, and especially avoids engine warning light. If idle instability, exhaust pipe black smoke, or loss of power occur, replace promptly.