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Q: Misfires at high speed on a high way

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The car moves smoothly at high speed up to 100miles per hour, but when I push the pedal down (kick down) to overtake other vehicles the engine misfires, showing check engine light. When l reduce speed a little, the engine regained full power and the check engine light disappears from the dashboard. Best regard.

My car has 100000 miles.
My car has an automatic transmission.

Hello there, a few common faults will cause your 2004 BMW 540i to have a misfire on acceleration. Without knowing what code the engine is storing I can only offer general advice. Likely causes for the car to misfire like this would be the fuel pump, fuel filter, spark plugs, coil pack, throttle body faults, or a wiring harness issue. Since the problem only occurs when the pedal is pressed at first this tells us a part is on its way to failing, but has not fully yet. A qualified Technician such as one from YourMechanic will be able to diagnose your misfire condition and make any repairs required to resolve the issue.

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