Emulator used on Citroën and Peugeot vehicles built from 2007 on and with CAN type OBD connector, to reset the fuel gauge, which indicates a dropping petrol level while the vehicle is running on gas.
In the some modern cars, when the engine is started the fuel level is determined based on readings from a sensor in the fuel tank. Then fuel level is adjusted by a computer on the basis of current pet..
On the market there are engines without vacuum in intake manifold (like valvetronic type: BMW, VOLVO). In this engines can be difficult to make proper calibration of sequential gas injection system. F..