Hi you really need to get the fault codes read,but i would hazzard a guess at the code showing up as the knock sensor.
However it wont be the knock sensor it,ll be one of the injectors that is at fault.
Quite a common fault,seen it a lot on the tdci mondeo,s.
Your best bet would be ford im afraid to say as they are the only people that i know of that can reprogramme new injectors if that is what it needs.
Richard
rbtrans@hotmail.com
Richard
November 2008