Do all modern Vehicles Petrol and Diesel have MAF sensors?

Almost all modern gasoline vehicles have a MAF (Mass Air Flow) sensor. Diesel engines do not have MAF sensors because they measure the amount of air going into the engine using a MAP (Manifold Absolute Pressure) sensor.

A MAF sensor is a device used in internal combustion engines to measure the mass flow rate of air entering the engine. This information is used by the engine control unit (ECU) to calculate the correct fuel-to-air ratio for the engine.

A MAP sensor is a device used in internal combustion engines to measure the absolute pressure of the air in the intake manifold. This information is used by the ECU to calculate the air density and the mass flow rate of air entering the engine.

Diesel engines do not have MAF sensors because they do not need to know the exact mass flow rate of air entering the engine. This information is not necessary for the ECU to calculate the correct fuel-to-air ratio for a diesel engine.

Instead of a MAF sensor, diesel engines use a MAP sensor to measure the absolute pressure of the air in the intake manifold. This information is used by the ECU to calculate the air density and the mass flow rate of air entering the engine.