Awasome Fuel Additive Check Engine Light References. Keep in mind that the fault code that caused the light to turn on in the first place is stored in your car’s onboard. The gas cap seals the fuel system, and if it is cracked or not fitted properly, it will trigger the check engine light.this will cause your vehicle to fail the smog test.

If your check engine light is coming from an underlying fuel system issue, this is the product you want. Web the check engine light is a small icon with a vehicle’s gauge cluster which illuminates if the vehicle’s ecu, or “electronic control unit”, receives a fault code from one of its sensors, actuators, or systems. Turn off your music and listen to your vehicle and the engine to see if it sounds like it is struggling or misfiring in any way.