5. FUEL INJECTION SYSTEM MOVIE S 150i Oxygen Sensor consisted of Heater and Non-Heater Types: Non-Heater type Sensor does not have heating function and is heated by exhaust gas and it takes longer time to reach working temperature and once the engine is idled for too long, sensor temp will drop and sensor stop working. Heater type Sensor has the heating function to make it reaching working temperature earlier and always maintain temp of working condition. Kymco and Piagu use heater systems. Sketches of Circuit Control of Open and Close Loop systems Circuit Sketch of Open-Loop system Micro-processor Control Unit Fuel Injector Engine Gas Exhausting Circuit Sketch of Close Loop System Feedback of Signal of too thick or too thin correction Micro-processor Control Unit Fuel Injector Engine Waste Gas Exhausting Injection quantity Modes of Trouble Detected high CO content, Engine Checking Lamp on, Engine Checking Lamp flashes from time to time. Cause 1. Broken lead wire (curved / bent, stretched, twisted or angle more than 90 degree, or is not fixed to fixing clip at time of installation of main body lead wire, or the wring set has too long suspension, or in cross-connection, the lead has too short turning radius (shall be >/= 20 mm) 2. Loose lead wire connector 3. Burnt appearance 4. Broken of short of inner heater coil 5. Break of inner heater (crash on vehicle frame when dismounting) 5-35