Audi A4

since 1994 release

Repair and operation of the car



A4 Audi
+ Running gear
+ Regular servicing
+ Engines
+ Turbo-supercharging
+ System of an exhaust
+ Cooling system
+ Fuel tank and fuel pump
+ Air filter and channels of absorption
- System of injection
   + System of injection of Motronic
   - System of injection of MPI and MPFI
      Additional functions
      Knots of system of injection
      Functioning
      Adjustment with the help a lambda probe
      Violations in work and self-diagnostics
      Self-help
      Visual control
      Check of knots
      Dismantle of separate details
      Cable of a butterfly valve
      Inlet collector
      Idling adjustment
      Check of exhaust gases
      The help at malfunctions
+ Coupling
+ Transmission and main transfer
+ Suspension bracket of wheels and steering
+ Brakes
+ Wheels and tires
+ Electrotechnical equipment
+ System of ignition
+ Lighting
+ Alarm equipment
+ Tools and devices
+ Heating and ventilation
+ body Details
+ Salon
Search of malfunctions
Technical characteristics





Adjustment with the help a lambda probe

The catalyst can work effectively only in that case when the relative amount of air l (lambda) as much as possible comes nearer to 1. That to receive it, the system of ignition/injection of MPI/MPFI is supplied so-called a lambda adjustment. Thus the lambda probe measures in exhaust gas amount of oxygen – comparative size for definition of composition of fuel and air mix. If the measured size deviates from ideal, the control unit carries out additional adjustment. Adjustment functions in the range from l=0,8 to l=1,2.

The lambda probe gives a signal, suitable for use, only at temperatures over 350 °C. Quickly to reach this temperature, the probe is warmed up in the electric way. Before the necessary temperature is reached, the system is not regulated and guided in the set average size l.

The six-cylinder Audi model with the all-wheel drive has two catalytic converters and two lambda probes.