If you find that your car is suddenly getting bad gas mileage, or mileage has worsened after a tune-up, then the device responsible could be the MAP sensor. These little devices pick up on the voltage being delivered by the car engine, and then relays this information to the car's computer, which then causes it to decrease or increase the fuel consumption. But if your MAP sensor is feeding the wrong information to your computer, then you will find that combustion is disrupted, ragged, or even excessive, and your engine performance is poor. In order to decide if your MAP sensor needs to be replaced, you should try a few troubleshooting steps.
