Hi friends.
i had check engine light came in mornig, so went to mechinic and told me code P0031, bank1 sensor 1 Heater control circuit low. its oxygen sensor. but where do i find this on car? ?? i mean where does it located. i dont know which is b1s1 or b1s2 or b2s1 ??
can you help?? so i can replace it by myself bcus mechinic ask for 500$
thanks

 

Do you mean code 0131? If so B1 S1.

For 4 cylinder, this would be first sensor on exhaust sytem coming from the cylinder head. If V6 same but on the cylinder head closet to the firewall.

If changing the sensor suggest using Denso brand (or Toyota).

What year car and engine model?

 

I would def. spend the extra money and get the Toyota part. I've had issues with all the aftermarket ones that i've used.