A check engine light may be illuminated due to a vacuum or emissions leak which can be as simple as a loose gas cap. in the 2019 ford ranger, more serious reasons include a faulty o2 sensor or a failing catalytic converter. t an o2 sensor often needs to be replaced if you suddenly notice a drop in fuel economy. it's responsible for monitoring the amount of unburned oxygen in the exhaust and conversely provides a key piece of data to the engine's combustion system in determining its air/fuelratio. the cat helps transform carbon monoxide into carbon dioxide and can become clogged and d***y over time. when the ecu senses imbalanced emission readings, the "check engine" light will be illuminated. if any one of these processes become interrupted the "check engine" light in the ranger will switch on.
The 2019 ford ranger check engine light is usually caused by a loose gas cap or sensor on the engine.