What does it mean that the control circuit voltage of Citroen C4L oxygen sensor is low?

The control circuit voltage of Citroen C4L oxygen sensor is low, indicating that the oxygen content in exhaust gas is high, which leads to a small difference between the exhaust pipe and the outside oxygen concentration, so the circuit voltage of oxygen sensor is low.

Oxygen sensor is the key feedback sensor in the control system of EFI engine, and it is the key component to control automobile exhaust emission, reduce automobile pollution to the environment and improve the fuel combustion quality of automobile engine. Oxygen sensors are installed on the engine exhaust pipe.

Causes of low voltage in control circuit of oxygen sensor

The continuous low voltage signal indicates that the mixture may be too thin and the oxygen sensor itself is faulty.

The blockage of fuel injector and nozzle hole may lead to the failure that the fuel injection quantity of individual cylinders is too small and the mixture is too lean. In severe cases, the fuel injector will not inject fuel. When the fuel pressure is too low and the fuel injection pulse width is constant, the fuel pressure is low, and the circulating fuel injection quantity is reduced, resulting in too lean mixture.

There is unmeasured air between the air flow meter and the throttle. The leaked air here has not been measured by the air flow meter, and the signal from the air flow meter to ECU is wrong, which leads to too little fuel injection from the injector and too lean mixture.

Gasket between intake manifold and cylinder head is leaking. As a result, some intake manifold pressure sensors did not detect it, resulting in relatively reduced fuel injection and too lean mixture.

The carbon canister solenoid valve of the fuel vapor recovery system is usually open. Make the engine under idle speed, low speed, light load and high speed (n >: 4000 ~ 4500 r/min) full load, sudden acceleration or deceleration, engine water temperature < 55℃ and other transitional conditions, and the mixture is too lean.