I would have told you the first thing to do is to read the code yourself so you know what the problem is before going in. You can do that with our CAN Tool or a JB4. If you don't have a code reader and don't want one then always remove any mods before going in.
In terms of the actual problem if you have the specific code I can give you better advice on it.
so FYI guys although they say it will not trigger any warning it will . In my case it did and now i should buy a CAN tool? i guess live and learn!