ford mondeo2002

2002 Ford Mondeo
I have an orange light flashing on dash and since it came on I have lost the power of the turbo and it runs average but was hard to start when cold and as it starts a lot of white smoke and no revs for a few seconds so had the heater plugs done and the injectors and still no engine performance and sluggish start this morning and a little smoke. what can it be please?