Question

Fault Code P0128 - Cooloant Thermostat Malfunction.
Changed the car engine recently and the technician removed the coolant thermostat while fixing the new engine. Engines runs perfectly and doesnt overheat, but just dont like the fact that I see the information on my dashboard staring at me.

Answer 1

why did he remove the thermostat? the light is going to come on because the car is not getting up to temp.

you need to put the thermostat back on or run of step cooler thermostat