Name some symtons, if missfiring it could be the coilpack. If revving to around 2k then down to 200rpm then it maybe the maf sensor. Have you had a service recentley?
On the pick below disconnect the sensor i have marked, don't worry it won't damage the engine. Turn the car on and then test drive it, this is a common problem on Mondeo's (well zetecs in general) also what Year is your Mondeo?