Toyota Corolla "Check Engine" Indicator Lamp : Solution?

Toyota Corolla "Check Engine" Indicator Lamp : Solution?
In Toyota Corolla, there are certain sensors inputs to ECU Engine Control Unit which can trigger "Check Engine". These are.... Engine coolant Temperature sensor Mass Air flow sensor Crank shaft Position Sensor Throttle position sensor Park / neutral gear Selector Position Vehicle Speed Sensor Knock Sensor Power steering Oil Pressure Intake Air Sensor Fuel / Vapor Pressure Absolute Manifold Pressure Oxygen / Air-fuel Ratio Sensor If you can start and steer your car well, and still Check Engine light remains on you should target last three sensors. Possible causes are: 1. improper fuel pressure. Leak in fuel system, may be pin-hole, To detect this fill-up your tank to the maximum, park your car in a clean space for a while 5 to 10 min. and check the for the fuel leak on the bottom, if there is any, may be because of Missing Gas Cap, Fuel intake pipe, Gas Tank or Fuel lines. 2. Leak in Exhaust system. Can be detected and fixed easily. 3. Fuel injector restricted. Use Fuel Injector Cleaner several times. 4. Defective heated Main oxygen sensor No. 1. If you are very sure about 1, 2 and 3, then target main oxygen sensor located after exhaust manifold and before catalytic converter. Replace this with brand new one after replacement disconnect battery positive terminal for a while and reconnect it. Start the car and see if Check Engine light turn on after a while replace sub oxygen sensor after catalytic converter and before exhaust tail pipe. After replacement disconnect battery positive terminal for a while and reconnect it. Start the car and see if Check Engine light turns on after a while target following sensors in sequence. 5. Defective Manifold Absolute Pressure (MAP) sensor. 6. Defective Engine Coolant Temperature (ECT) sensor. 99.9% your problem will be solved at the step 4. GOOD LUCK!!!