OK so the Lambda should be OK. But still do the test, and see if it oscilates. If this does not work, and as you say the engine runs smoother without the lambda (In limp home mode) this indicates that there still is "gremlins" in the exhaust "follow up/feedback system".

The next Idea i have is to ask one of the suppliers that sell chip upgrades. Some of these guys really know what they are talking about. And he would definetly be able to tell wether the lambda function is working or not if he hooks the car up to hes computers. Tell me if you do, bacause I would really like to show up and learn - If you don`t live to far away.

Best reards from Eidsvoll.