I've heard Hondas don't get along well with Bosch spark plugs, but haven't heard that about O2 sensors.

You read code 41 by the flashing CEL method? That's really the same way for any shop to do it.

Or are you referring to the multi-meter? That's RadioShack or someplace like that. Volt-Ohm-Ammeter, whatever. AutoZone has cheap ones too. Check electronics supply type stores for better meters.