Q: Engine Light comes on and car wont accelerate

asked by on February 02, 2017

When driving my 2012 Mercedes c250 at normal speeds the car will all of a sudden jerk almost like you tapped the brakes but you didn't and then the Engine light comes on and the car wont accelerate over 15 to 20 mph. You can hold the gas pedal to the floor and nothing happens. You then have to pull over to the side of the road and turn the car off. After a few seconds you turn the car back on and you can again accelerate however the engine light stays on. The engine light will usually go off after a day or so. This same thing is now happening about ever other day. I am very worried that I am going to be on the highway going 65 mph and this issue is going to happen which could cause a really bad accident. Does anyone know what the problem is and what I need to do to get corrected? Please any help would be extremely appreciated.

My car has 55000 miles.
My car has an automatic transmission.

What you are describing sounds like a dirty or faulty mass air flow sensor. The mass air flow sensor monitors air intake as it is mixed with fuel prior to being injected into the motor. This sensor relays vital information to the ECM which uses this to make adjustments to fuel supply to the motor. A dirty or faulty sensor can cause 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 bit of black exhaust smoke and typically a strong smell of fuel when this sensor is malfunctioning. I would suggest having a professional from Your Mechanic come to your home to diagnose and inspect your vehicle.

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