when i was working at oreilly's, a guy came in and asked for the cheepest one wire o2 sensor we had. this got us instrested so we asked what it was for. he said you can take a one wire and a DMM or DVOM and hook the possitive to the o2 sensor and ground the negitive(sp) and set it on straight volts and .1 is lean and .9 is rich and it actually works. just thought someone would like to know
