1997 Honda Civic O2 censor

What exactly is the code?

You may have an open or shorted wire in the circuit, did you check the wiring going to the sensor?

What my colleague asked for is the ACTUAL CODE NUMBER, not just description. But, if I understand your description correctly, you said Heater Sensor Bank 1 Sensor 2. And you were told it was the cat converter.

Those people are wrong. It has something to do with your rear O2 sensor harness going back to the ECM. Your O2 sensor grounds at the ECM, and that circuit is bad. So, go under the car and make sure that the harness is connected tight, and follow the wires as much as you can to make sure that it is not cut, frayed, etc.

But we still need the actual code numbers to be accurately sure.

Like Zackman said. It sounds like you were told it was Bank 1 Sensor 2, which is your post-catalytic oxygen sensor.

However, we need the code number to help you determine what is going.

If it is the heater code for your secondary o2 we can post up how to test the wiring for the heater circuit if you indeed did replace the proper o2.

Check continuity on all highlighted circuits. Repair any open circuit. If all circuits are good, replace the O2 sensor. It can be a major PITA to find bad wire. Just imagine you have to connect one end at the O2 sensor connector (under the car) and the other probe in the kick panel. Once you know the bad circuit to repair, ten you have to literally trace the wires. But it can be fun-filled, knowledge-seeking adventure.

Do you have an Autozone close by? They can can scan your ECM for free..

Let us know what you find out.

Unplug your rear O2 sensor (after the cat). Also unplug the corresponding connector plug on the PCM. CAUTION: Only unplug one harness at any one time. We are not testing the O2 sensor or the PCM, rather the wiring harness itself. So do not hook up the probes to the O2 sensor or PCM sides. Both probes have to be attached to the wiring harness plug.

Set your multimeter to resistance (ohm). Place one test lead to the connector end (at PCM) and the other at the O2 sensor.

1. PCM connector A5 (BLUE) and sensor side (black/white) wire.
2. PCM connector D13 (GREEN) and sensor side either green/black or red/yellow.
3. PCM connector D14 (RED) and sensor side white/red.

All 3 tests should result in 0 ohm reading. If you have any other number, that wire is bad.

Attach extension wires such as Dorman 85654 to your test leads. Just make sure that they don't touch any metal of the car. "Zero" ohm means continuous wiring, "infinity" means bad or broken wiring.

Sorry I couldn't be more of help. But just ask them to test the circuit before replacing the ECM.