Hi. have a check engine light on my 2006 hawkeye R sport non turbo, I have scanned the car and it says code P0037 Oxygen Sensor Heater Controll Curcuit, low Bank 1 Sensor 2.

I replaced the lambda sensor with a genuine subaru one but it didnt fix the problem, a mechanic told me its a fualt with the lambda sensors heater controll and could be a fuse, relay or wiring The car has done 115000 miles and exhaust is stock and car has no mods

does anyone know if there is a fuse or relay or anyone had this problem before, any help appreciated. thankyou

 

Which sensor did you change?

 

Rear sensor , was genuine part too

 

For clarity, Rear O2 sensor is the one directly below the RH valve cover.
Subaru Denso OEM replacement P/N's 22690AA831 or superceded by 22690AA970
Denso P/N DOX-0361

If there was a problem with the relay then you would also have a P0032 (HCCL Bank 1 Sensor1 A/F sensor) as it powers both sensors
Relay supply marked below.....


is a common ground with various other engine sensors