One cylinder not working in a car engine?

Question

Is that bad? Its an 01' expedition. Will the car make any type of noise, what can happen?

Answer 1

It means that for some reason, 1 cylinder is not firing, which means it is not contributing to the power of the engine. This can absolutely KILL your fuel economy. You may notice the engine seems to run rough or maybe start to seems like its shaking, that's because it not running balanced and the other cylinders are having to try to make up for the power its not giving.