1998 Maxima - P0155 and P0325

Receiving both codes. There is no noticeable difference in the way the car runs or idles. How important is it to replace both parts quickly? Would one cause the other to show a malfunction code?

Thanks!

I don't think P0325 will set your MIL light, but P0155 should. So, both codes refer to an unexpected voltage in the circuit. P0325 refers to the knock sensor circuit(1wire sensor) and P0155 refers to the O2 sensor HEATER circuit. Because both of these sensors are located on the under side of most engines, they probably share a wiring loom and it is concievable that both could be throwing codes because maybe they're laying on something they shouldn't and have rubbed through. First I'd check my harness by finding the O2 sensors and knock sensors and following the wires visually and watching where they go and look for anything they're rubbing on. IF you can't find anything visually(make sure) then there are some tests you can do.

Find bank 1 knock sensor and unplug it. Turn key on engine off. Should have 5V at the connector. If not=there's an open somewhere. If so= PLug it in and backprobe the sensor. SHould have about 2.5 volts now with key on engine off. If you have no voltage, suspect bad knock sensor. If you have still 5 Volts, suspect a knock sensor or the connector.

As far as your Bank 2 O2 sensor code:It refers to the Heater circuit inside the o2 sensor, NOT the o2 sensor itself. Usually it's a fault inside the sensor, but not always. If there are no harness problems, then unplug the sensor(bank 2 front sensor) and turn key on engine off. There should be 12 volts at the light green/blue wire. If you have that, it's easier to replace the sensor at this point then to troubleshoot the heater circuit(for the layman)

@webmaster
Hey that looks sharp. Thanks for the flash!

Thank you Darkrooms, I will give it a shot this evening.

I sent you a PM about that.