My 99 escort has suddenly started running very rough

Question: My 1999 Ford Escort 4 Cyl 2.0 has suddenly started running very rough it seemed like spark plugs and wires but i changed those and it didnt help. check engine light came on and code read vehicle speed sensor. would that cause these symptoms? Already Tried: Spark plugs and wires. air filter. my gas mileage has slowly dropped with this problem Answer: If the engine id running rough at idle, I would recommend replacing the coil assembly as this is a common issue with the Escorts. If it idles fine and only seem to run rough(shift at abnormal points) then Yes, it is being caused by the vss sensor. Drive One! (this code will appear as a text link, but when clicked will load the widget)