The inductive pickup goes over the spark plug wire to cylinder #6. This "sensor" directs the dme to split injector duty between 2 banks of 3 each. The 1.3 motronic on the 535's allows for 3 injectors to fire at a time, instead of earlier versions firing all 6 injectors together. This prolly won't cause a noticeable problem in driving.
Get the correct Bosch silber spark plugs for the m30. M30's don't like platinum plugs. This is likely yer problem.