Ok so i check sensor

I have 4500 ohms and this resistance drops as i heat the sensor with a heat gun

I then checked the resistance between the black wire going into the sensor and the green/red wire at the plug into the ecu. Same resistance.

So its either the black wire (which i assume is an earth??) Or something inside the ecu.

So my question is where does that black wire go to earth? Its nicely wrapped so avoiding pulling it apart would be nice.

 

Problem solved. The earth wasnt...well earthing.. the set of earths undernesth the washer bottle (right hand drive) were clogged up with *****. Stable iat reading for everyone horray \(-_-)/