I have a CEL, Honda tell me it is because of the ECT sensor (something to do with Coolant temperature sensor?), when it was in last week they reset this and said if it comes back to call.

It has come back so the car is going back in to be checked. They reckon if it is this sensor again that it should be

 

Replaced mine few months back, it's tricky to replace as it's buried at the back of the engine against the firewall, not much room..