http://www.pocketlogger.com/?pid=rte...2&ecu=S5NA#mop
On the S5 series, the oil injection pump (MOP) is electronic and controlled by the ECU. If the ECU detects a failure of the MOP it will enter limp mode. This makes removal of the pump impossible with the stock ECU. The MOP Removal feature defeats the operation of the pump and detection of pump failures (codes 20, 26, 27 and 37), thus allowing complete removal of the pump. Premix or the more reliable S4 mechanical pump can then be used.
In the Stage 2 ECUs, this option can be turned on and off using the control software.
CAUTION: This mod should not be used if you intend to continue operation of the electronic MOP.