I have a 1995 E320 w/ 180,000 bought used at 145,000. Car has been idling up and down (surging ) for about 4months but yesterday it has started to accelerate sluggishly and this morning it "backfired" on me. Its as if the fuel filter is dirty but I dont think that is the problem. The ECU codes are 10,16 and 19. Could this be a O2 sensor gone bad?