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Q: Engine surging and speedometer dropping?

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I have a 2.7l 2007 Dodge Charger. Every now and then while driving at highway speeds the engine will surge for a split second, and the speedo will drop about 30mph at the same time. After about half a second it's back to normal

My car has 100 miles.
My car has an automatic transmission.

This is somewhat common when your mass air flow sensor is dirty or faulty. The mass air flow sensor is a unit in the intake system that monitors air intake as it is mixed with fuel prior to being injected into the motor. When this is dirty or faulty, this causes an imbalanced air/fuel load to be supplied to the motor which results in an over fueling or under fueling situation depending on the conditions. This type of inconsistent fuel supply to the motor may cause a hesitation, loss of power, a jerking reaction, potentially a bot of black exhaust smoke and typically a strong smell of fuel when this sensor is malfunctioning. When this is not working properly, you may also notice a strong smell of fuel. I would suggest having a professional from Your Mechanic come to your home to diagnose your mass air flow sensor.

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