My car is bucking at low speeds and while in drive at sto...

Q: My car is bucking at low speeds and while in drive at stop signs and red lights no codes it's an '06 expedition.

asked by on August 14, 2017

My car bucks at low speeds and stops when in drive. There are no codes. I changed all coils and plugs and o2 sensor (bank 2 upstream). What could the problem be?

My car has 167678 miles.
My car has an automatic transmission.

It sounds like you may have a crankshaft position sensor that may be on the verge of failing. A crankshaft position sensor is an electronic device used to monitor the position or rotational speed of the crankshaft. This information is used by engine management systems to control the fuel injection or the ignition system timing and other engine parameters. When this is faulty or not working properly, this will cause problems with the ignition system and generating spark transmission to the spark plugs resulting in starting problems and other performance issues causing misfires. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

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