Check Engine Light “On”
If your check engine light is illuminated, it’s best to take it in for diagnostic testing. Because while the lights vary in appearance from vehicle to vehicle, all have the same basic meaning: There’s a problem with the car’semissions system. The on-board diagnostics system and engine control unit are in charge of monitoring a bunch of different parameters, and if they get a reading that’s a little out of whack, up pops the check engine light. Check to make sure your gas cap is on and give it a few more clicks to tighten it up. If that doesn’t work, head to a mechanic. It’s always a good idea to get a professional to diagnose the problem. It may be a wet engine, a blown gasket head, faulty oxygen sensors, worn-out spark plugs or spark plug wires, loose or cracked hoses and manifolds, sticky exhaust gas re-circulation valves, or pinched or deteriorated fuel injector O-rings.
According to statistics, most engine lights are caused by oxygen sensor failure, your gas cap is loose, catalytic converter trouble, bad spark plugs/ignition coil, bad spark plug wires, mass air flow sensor, poor quality aftermarket car alarm system, bad vacuum hose, exhaust gas re-circulation valve maintenance, and dead battery.