97 Es300 P0135 Oxygen Sensor Bank 1 Sensor 1

[diehippiedie]

Hi Everyone,

Check Engine light came on recently on my 1997 ES300, OBD scan showed P0135 Oxygen sensor heater circuit Malfunction (Bank 1 Sensor 1).

Now I assume I just need to change the O2 sensor itself, so I want to locate this B1S1 sensor. After downloading the 97 ES300 service manual, I found some discrepancies in the manual about the location of the sensor:

I know Sensor 2 is the downstream sensor on the exhaust, but Im confused about the location of Bank 1 and Bank2

One of the pages showed:

And the other page:

Clearly 1st pic showed the B1S1 is on the front of the engine whereas the 2nd pic showed the B1S1 on the back. So exactly which one is right? From my research looking at a 94 and 2000 model it seems like the second pic, which is between engine and firewall. I just want to make sure. And also, is changing the sensor actually the right remedy for this problem? P0135 is the only code surfaced. I appreciate any suggestions you can offer.

Thanks so much!!!

[George_Jetson]

Bank 1 references the bank which cylinder #1 is located in. So in your case, you want to replace the one next to the firewall (which is a real pain in the butt to get to. It is easier to get to from underneath the car. If you decide to go this route, make sure that you use a good quality jackstand to lift the car. Do not get underneath the car while it is on the car jack. Your typical carjack is barely safe enough to lift the car to change a tire.

[diehippiedie]

Thanks for the safty precausion, and yes I found the sensor and looks really hard to get to from the top. I think i'll just go ask a mechanic to swap it for me. <_<