Hi , I have a Defender TD5 pick up 2003. A couple of weeks ago while in idle I noticed the idle went from normal to a rough idle and it has stayed the same ever since. After inspecting the Mass Air Flow sensor I noticed one of the little wires was missing so I have replaced the sensor only to find the same idle problem. On cold start in the morning she struggles and a constant clicking sound is heard under the drivers seat, not sure if that's the ECU or a relay. I have also noticed that when she starts the idle is normal , then a clicking sound from below the seat and idle changes to rough. Any suggestions as to what might be causing this.