Since you always seem like one of the best sources of information on this site I'll ask you. Should I be scared of or return the new Bosch 16123 O2 sensors I have? Are they correct or not? I also read on this forum that Bosch 13782 was the correct one. When I asked about it in a thread last night someone came back with yet another Bosch part number. BTW it is a 1999 ML320. Thanks again for your time.