Originally Posted by
stndrd
don't have such tunnel vision as to what it could be. You will find alot of cars can go up to 150-200,000km without needing an O2 sensor changed as even tho they have excess carbon build up, they still read quite accurately and are not faulty. On the D16Y engines there is only a single O2 sensor. I think you will find that a good quality on car injector clean will work better wonders that replacing an O2 sensor, as on car injector chemicals are designed to dissolve excess carbon build up.
With the temp gauge being faulty, you need to remember that there are two temp sensors, one is a temp SENDER, that sends the signal to your dash, then there is your temp SENSOR (which is a negative temp coefficient sensor) and this is the sensor that you need to check to see is faulty or not. Your temp sensor is the one that tells your computer how hot or cold the motor is, therefore helping the computer to determine appropriate afr's. If when tested, the coolant temp sensor has a high amp reading, even after letting the car warm up until the thermo fan comes on, you will have a faulty temp sensor as it will be saying that the engine is cold and the ecu will over fuel your motor