hi guys when these are on the last legs what does it make the car do? smoke n overfuel? i.e. black soot

 

idle strange/missfire

get hold of a scope and see if its working correctly

 

Coolant Temp Sensor Checking - info courtesy of Simon @ SECS
1) Ensure ignition is OFF.
2) Remove rear of ecu plug cover and insert plug back into ecu.
3) Turn ignition back on (do not start engine)
4) Check resistance between pins 29 and 11. Should be 800 to 5000 ohms (depends on temp). If outside this range, check sensor and/or wiring.