Hi I have 05 td4 and there is no sign of any cable or plug for air temp sensor on intercooler hose. My 03 td4 never had this sensor. Not sure if this might be my problem with lumpy tick over and smoke on cold start. Runs perfect after a minute drive.

No that sensor makes little difference if it's connected or not when cold. It has more of an effect when warm though, but still not a huge effect.

Smoke and rough running just after cold starting could be an injector leaking slightly or a glow plug not working. I have similar missing and smoke on starting which I know is a glow plug. I just ignore it as the plug won't come out.