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    2002 Oldsmobile Truck Bravada AWD 4.2L SFI DOHC 6cyl

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    Get to Know Your Dashboard Lights

    You may be wondering why your Check Engine Light is on. Is it a major problem or something minor? AutoZone is here to help with the top 5 reasons your Check Engine Light may come on.

    1. Your Oxygen (O2) Sensor needs replacing

      Your oxygen sensor measures the amount of unburned oxygen in your vehicle's exhaust system.

      What if I don't replace it?

      • Your engine will burn more fuel than needed
      • You will experience loss of fuel economy (up to 40% if ignored)*
      • Faulty sensor(s) can cause damage to your spark plugs and catalytic converter
    2. Gas cap is loose, damaged or missing

      Your gas cap seals the fuel system and helps maintain pressure within the fuel tank. It also prevents gasoline fumes (hydrocarbons) from being released into the atmosphere while you aren't driving your car.

      What if I don't replace it?

      • You can lose fuel through evaporation
      • You may make more trips to the gas pump
    3. Catalytic Converter needs replacing

      Your catalytic converter helps protect our environment by converting harmful carbon monoxide into carbon dioxide. Damage usually occurs due to neglected maintenance (reasons # 1, 4, and 5).

      What if I don't replace it?

      • Your vehicle will not pass an emmissions test
      • You will experience reduced performance and fuel economy
      • Your car may run at a higher temperature
    4. Mass Airflow Sensor needs replacing (MAF)

      Your mass airflow sensor measures the amount of air entering the engine to determine how much fuel is needed to run your engine efficiently.

      What if I don't replace it?

    5. Spark Plugs or Plug Wires need replacing

      Your spark plugs ignite the air/fuel mixture in the combustion chamber of your vehicle. The spark plug wires deliver the spark from the ignition coil to the spark plugs.

      What if I don't replace it?

    * www.fueleconomy.gov
    ** Service not available in California

    Of course, there are various other causes of an illuminated Check Engine Light. You can depend on the experts at your local AutoZone to help you find out what the problem is for free**. Finding out may help you save gas and avoid more problems down the road. Parts are just part of what we do.

    What It Takes To Do the Job Right

     
     
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