The 1995 Toyota 4Runner fuel system is equipped with Multiport Fuel Injection (MFI) system. The MFI system is composed of three basic subsystems: Fuel, Air Induction and Electronic Control Systems. The Multiport Fuel Injection (MFI) system receives signals from various sensors indicating changing engine operating conditions such as: Intake air volume; Intake air temperature; Coolant temperature; Engine rpm; Acceleration/deceleration Exhaust oxygen content etc.