P0155

[Dr_Shakalu]

Just changed my egr solenoid and egr valve. I'm getting a P0155 on my scanner regarding the passenger side oxygen sensor. I believe the oxygen sensors have never been changed. Should I just change the sensor that's giving me the code ir should I change both sides? Also, how hard to change and any directions are appreciated.

 

[speed367]

Most of the time o2 sensors dont go bad. You should hook a scanner up and see how the o2 sensor is performing. Make sure you dont have a vacume leak or anything like that.

 

[Hib Halverson]

DTC P0155 is the fault code for the heater circuit for the front sensor on the right bank.

Before I'd go buy O2 sensors, I'd diagnose the O2S heater circuit, first.

The engine controls' wiring diagram and troubleshooting instructions are in the Factory Service Manual for '96.

 

[Dr_Shakalu]

DTC P0155 is the fault code for the heater circuit for the front sensor on the right bank.

Before I'd go buy O2 sensors, I'd diagnose the O2S heater circuit, first.

The engine controls' wiring diagram and troubleshooting instructions are in the Factory Service Manual for '96.

I also wondered about the heater circuit. I have the FSM and will look it up. Do you happen to know what page it's on and is it easy to test. Sometimes it takes me forever to find something in the FSM and I hope it's not too hard to test because I don't know alot about electrical problems. Thanks, Ed.

 

[ecss]

The O2 sensor in question is on the passenger side exhaust pipe before the cat converter.

There is a 4 pin connector plug that plugs into the o2 sensor as shown in the diagram below.
One end of the cable leads back to the PCM.
You unplug the connector. Set the meter to read DC volts. Turn the ignition On.

On the plug end that goes back to the PCM place the Black test probe on Pin C the Black wire and the Red test probe on Pin D the Brown wire. You should measure 12 volts.

The same 12 volts is used by the other two O2 sensors so it's unlikely you won't measure 12 volts.

If no 12 volts verify the Oxygen Sensor fuse located in the passenger side end of dash fuse panel is good.

Turn the ignition Off.

If the 12 volts is there the only thing left to verify is if the o2 heater filament is Open.

Set the meter to read resistance/ohms. Place one probe on the plug going to the o2 sensor on Pin C and the other probe on Pin D.

Should read a low resistance like 6 ohms. If you read infinity/open the heater filament is bad and the o2 sensor needs to be replaced.

If you're not mechanically inclined purchase a new o2 sensor and take it to an exhaust shop and let them install the sensor. Sometimes a torch/heat is needed to get the old sensor out.

Make sure when you are done you secure the wiring harness so it doesn't get damaged from the heat from the exhaust.

 

[Dr_Shakalu]

The O2 sensor in question is on the passenger side exhaust pipe before the cat converter.

There is a 4 pin connector plug that plugs into the o2 sensor as shown in the diagram below.
One end of the cable leads back to the PCM.
You unplug the connector. Set the meter to read DC volts. Turn the ignition On.

On the plug end that goes back to the PCM place the Black test probe on Pin C the Black wire and the Red test probe on Pin D the Brown wire. You should measure 12 volts.

The same 12 volts is used by the other two O2 sensors so it's unlikely you won't measure 12 volts.

If no 12 volts verify the Oxygen Sensor fuse located in the passenger side end of dash fuse panel is good.

Turn the ignition Off.

If the 12 volts is there the only thing left to verify is if the o2 heater filament is Open.

Set the meter to read resistance/ohms. Place one probe on the plug going to the o2 sensor on Pin C and the other probe on Pin D.

Should read a low resistance like 6 ohms. If you read infinity/open the heater filament is bad and the o2 sensor needs to be replaced.

If you're not mechanically inclined purchase a new o2 sensor and take it to an exhaust shop and let them install the sensor. Sometimes a torch/heat is needed to get the old sensor out.

Make sure when you are done you secure the wiring harness so it doesn't get damaged from the heat from the exhaust.

Thank you. I'll try it tomorrow.