I am slightly concerned as I fitted my new Eco3 box last Saturday and have not changed the setting from "7" as it was supplied. I have got an Astra 57 plate 1.9 cdti and have been running the box for the past week, covering a total of 300 miles. Until yesterday everything was fine when. I started her up and the engine slightly coughed (nothing major but not normal) then the engine management light came on. As soon as the light came on I disconnected the box, needless to say the light was still luminated.
I went to use the car this morning and when she started up there was no cough and the EM light turned off as normal. Starting a 40 mile trip the car seemed fine and after 10 miles I pull over and try the box. Same thing happened again, when I start the engine she coughs and the EM light says on. I disconnect the box and go back on my way but the car seemed to be in a "get home safe mode" for about a minute as there was a major flat spot when I pulled away in second and third gear. After that everything seemed fine, but the EM light was still on.
It is also worth noting that the car had the EGR valve replaced 3 months ago as the EM light came on.
Is it worth turning the box up or down? Why would the EM light come after a week/300 miles of use?
Any advice or help would be great.