Details

2004.5 S40 T5
Check engine light on.
Diagnostic reader gives two codes:
P0031 - HO2S Heater Circuit Low Voltage Bank 1 Sensor 1
P0037 - HO2S Heater Circuit Low Voltage Bank 1 Sensor 2

From what I could gather searching threads this is the oxygen sensor? Some threads pointed out two sensors, is this the case in my vehicle. Either way, could someone point me in the direction of where they are and how hard it is to replace them. Instructions or a site redirect to instructions would also be greatly appreciated. If this is not the oxygen sensor, help in what it is would be appreciated as well.

Thank you in advance for any and all help.

 

there is one sensor in the downpipe (before the cat) and a second sensor after the cat or in the middle of it.

wait for Tech, or someone to comment.....

 

Okay, I replaced both O2 sensors. Cleared the codes and then re-read and came back as pass. About 1 hour later the check engine light came back on. Took it back and the OBD gave me the same two codes. What's next?

 

Make sure there is no intake or exhaust leaks.

 

also check your fuses because your 02 sensors may not be receiving proper voltage due to a bad fuse...