[pzyroks]

A real n00b-question, but here goes...
When I connect a obd2-reader to my car, there is no signal from o2-sensor nr1. There is supposed to be 2 sensors, right? Pre and post cat. But i get no fault-codes. Shouldn't a defect sensor give a code? I've used Torque and ObdLink apps with an Obdlink Lx dongle.