Intermittent engine light fault 2017 Civic 1.0 turbo

[chris52]

I know this is a stab in the dark but I really am at my whit's end on this car. Story is the engine light came on and the car went into limp mode turned it off and restarted all good again but this started happening more often so took it to a Honda main dealer. They first said it was an injector so replaced that, then told me it was head gasket so started stripping down the engine only to be told it was a piston and that a nut from the turbo had come off and damaged piston number 2 quoted me over £8000 to replace the engine and turbo. I obviously rejected this and went to pick up the car. It was now in a thousand pieces. Strangley  enough all parts returned bar the damaged piston, no witness marks on the head and the bore as clean as a whistle. Anyway got my local indy to to fit a 15,000 mile tested engine to the car from a certified  vehicle breakers. this was done and the car started and guess what the intermittent fault is still there. I have replaced all injectors coil pack plugs fuel pump turbo (which didn't have a nut missing) etc etc. So I am back to square one.

The car picks up a missfire and puts it into limp mode. this only ever happens when you come to a stop at traffic lights etc. It does it with the stop start turned on or off and the only code you get is missfire detected usually cylinder 2. 

Honda have told me that it is not an ECU issue as they have tried another (to be honest though I wouldn't believe a word they say).

Has anyone experienced this problem or could possibly shed any light on it. 

Just as a side note it turns out that this is the 3rd engine this car has had as it was replaced by a different Honda Dealer while it was still under manufactures warranty.

Chris