So, we ground the TPS, CLT, and IAT to the MS, why not the O2 sensor?

I am using this as a grounding plan - http://www.msextra.com/doc/general/grounding.html

Thanks ~ JEB

 

The signal ground is grounded at the MS, that ground you see next to the o2 sensor is the ground for the heater element in it. I'm not sure all sensors even have that ground. I don't believe my Autometer does, but then I haven't actually wired it in yet...

Edit: Just looked at the wiring diagram for my Autometer wideband and it has both grounds, one for the heater and the other that would go to the ms.

 

If we are talking about a wideband, it should be grounded to the same point as the EMS. I generally place a ground stud on the EMS mounting panel to which I run all the EMS related grounds (wideband, ECU, etc.). The ground stud then has a lead that goes directly to the negative terminal of the battery. Others bring all the grounds out to the engine block and ground directly to the engine (after making sure the engine is well grounded).

Looking at the diagram, it represents a single wire narrow band O2 sensor which grounds through its metallic base.