CEL P0037 Rear O2 Sensor Replacement

ctrobk · Post by **ctrobk** » 14 Oct 2009, 14:57

Has anyone here replaced their rear O2 sensor?

I have an 03 V70 with 108k. I had to have the cat replaced at around 94k because the car was real sluggish.

The CEL came on, the reader showed P0037, "HO2S Bank 1, Sen 2, Heater Circuit Low". I reset the light, it stayed off for around 300 miles but its back on.

After inspection, looks like it might be a little hard to get at with a standard wrench. Do you need a "stubby" open end to replace it? Other than getting it out, looks just like an OEM plug.

Should I buy a direct replacement for about $180 or a generic and splice the plug for about $70?

Anything else I am missing on this or helpful hints?

Thanks in advance for your help.

Post by **MadeInJapan** » 17 Oct 2009, 07:39

Get the direct fit replacement- the one with the splicing just don't work well- even on older Volvo's, much less yours. There is also a special tool to get the 02 sensor out- looks like a box wrench but has a slot for the wire. You'll need plenty of PB Blaster and soaking time to get it loose- most of these over time seize in place.

ctrobk · Post by **ctrobk** » 17 Oct 2009, 19:46

Thanks Made, as luck would have it, the CEL went off yesterday. The same day I received the OEM 02 sensor. I will replace it, but the sense of urgency has passed with the light now off