I lost my gas cap can I buy a gas cap from O'Reilly or Auto Zone are do it have to come from the Mercedes company

Don’t panic. Here are five of the most common reasons why your check engine light might have come on in your Mercedes-Benz.

Check Engine Light Mercedes-Benz

1. Gas Cap

While your gas cap might not seem like the most important piece of equipment in your Mercedes-Benz, it actually carries a pretty important role. It maintains pressure in the engine and prevents fuel vapors from leaking out. In some cases the check engine light will come on when the gas cap is not tightly replaced. We suggest that you unscrew the gas cap and re-tighten until it clicks, then allow the check engine light up to a day to reset. A loose, broken, or missing gas cap can cause your vehicle to start jerking and lower its efficiency. If the light remains on after a day, take in to the service garage.

2. Oxygen Sensor

The oxygen sensor in your Mercedes-Benz monitors the percentage of unburned oxygen in the exhaust. Over time the sensor can get covered in ash; therefore, reducing its effectiveness and leading to a decrease in gas mileage and an increase in emissions.

3. Catalytic Converter

Your catalytic converter reduces exhaust gases by converting carbon monoxide and other harmful materials into harmless ones. Most failures are down to faults with other items, but a damaged catalytic converter can mean your car will fail its emissions test.

4. Mass Airflow Sensor

The mass airflow sensor allows your car’s computer to know how much fuel is needed based on the amount of air coming into the engine. Faults can decrease efficiency, increase emissions, and cause your car to stall.

5. Spark Plugs and Wires

Spark plugs and wires are responsible for creating the original spark that initiates combustion within your Mercedes-Benz, but they can fail over time. If yours are faulty, misfires will occur.

Your Mercedes-Benz Check Engine Light is never something you should ignore. While these reasons might not sound too serious, they can develop into a much more complex issue over time. See your mechanic.

Did you replace the gas cap? A gas cap that does not seal properly will allow air to be drawn into the evap system and will give you a corresponding check engine light and code. Caps are relatively inexpensive, so buy one and replace your old one.

Hello: Go to Auto Zone, Advance Auto or O'Reilly auto parts and they will get the code(s) for you and they probably will not charge you.

Yes...the cap needs to be on there or the purge system will register a leak. The light may not go out right away but usually will after about thirty miles of driving. (computer needs to go through a complete self test cycle).

Sometimes for this light to turn off you will need to reset the computer system that logged the code. Advance Auto and Auto Zone have a free service that will do this for you, they will also be able to tell you if the check engine light has logged a code for some other then the gas cap. Just go into Advance Auto or Auto Zone and say "Could you reset my check engine light for me?" they will grab their scanner tool and ask you to lead them to your vehicle, they will need to turn your car to the ON position but not start it.

fuel cap 96 gmc. locking cap 96 gmc. they should have the right one at auto zone or advanced auto. have a good day !

Go to auto Zone, tell them your problem and ask them if you can use their (new) gas cap (just for a minute) to see if that fixes the problem and if it does, buy the cap.

usually a few start ups or mileage will do or go to an auto store some scan vehicles for free such as auto zone / advanced auto check ur local area and have them scan and reset trouble code

WELL I WOULD FIND OUT WHAT THE CODE IS AND THAT MAY LEED YOU TO WHAT IS WRONG WITH JEEP I THINK YOU CAN GO TO AUTO ZONE AND THEY WILL READ CODE FOR FREE IF IT IS SMALL EVAP LEAK YOU COULD TRY GAS CAP BUT IF IT IS ANY OTHER CODE ITS NOT GAS CAP

I had the exact same problem, went to the Mercedes dealer and they fixed it for free with a pair of pliers. They just pulled up the metal clips and turned them back into place.