02 SENSOR WIRING DIAGRAM 1987 CHEVY PU 305

Part 1 -Testing the Oxygen Sensors (GM 4, 5, 5)
Jul 16, 2011Testing the oxygen sensor (commonly referred to as O2 sensors) on your 4, 5, or 5 GM vehicle is not that hard to do. Since oxygen sensors are not cheap and sometimes the PCM (Powertrain Control Module = Fuel Injection Computer) accuses them of being bad, when they aren't, testing them is a good idea and this article will help you.
4 Wire Oxygen Sensor Wiring Diagram | Free Wiring Diagram
Variety of 4 wire oxygen sensor wiring diagram. A wiring diagram is a streamlined standard pictorial depiction of an electrical circuit. It reveals the components of the circuit as streamlined forms, and also the power as well as signal links between the tools.