We have a 1996 Mercedes S320 that has code 36 oxygen sensor contorl sys lean stop/mix too rich, and code 84 short term self adaption idle\p load exceeded. Our scanner won't read more that this. The car idles a little rough at stops, feels like it may stall out and hesitates on acceleration. When the car came in, the air box clips were all undone. Does anyone have an idea what could be causing this?