08 Highlander Sport A/F relay

[foreman1063]

Anyone know where this guy is located? Got the dreaded P0031 code and want to check the relay before replacing the O2 sensor.

Thanks

[valkyrie]

The relay is located in the fuse junction boy left side engine compartment. But
it is likely not the relay. The relay powers both air fuel ratio sensors and would set codes for bank 1 and bank 2 if the relay was failing

[foreman1063]

Originally Posted by valkyrie

The relay is located in the fuse junction boy left side engine compartment. But
it is likely not the relay. The relay powers both air fuel ratio sensors and would set codes for bank 1 and bank 2 if the relay was failing

Good to know, thanks. Looks like sensor 1 is the one closet to the engine, any idea how accessible it is and how to tell which one is bank 1?
Thanks again

[valkyrie]

Bank one air fuel sensor is the firewall side closest to the exhaust manifold, most likely a little difficult to do, labor guide says 1 hour to do. I think it must be replaced from underneath, have not done one on a 3.5 yet. Good luck.

[foreman1063]

Thanks again for the help.