Rolodon

What does bank 1 code is p0171. Doesn't give me a sensor number to know which sensor it is . Is this the sensor by the firewall? Thanks for your reply

Nad1370

You are correct.
Firewall side is Bank 1

AF sensor in Bank 1(upstream) is on the LEAN side, (more air than usual) that the ECU can no longer compensate.

Rolodon

Thanks for the reply and that would be an upstream sensor ? Is there a difference in the way they make the sensors I just don't wanna order the wrong one

Nad1370

89467-41040 -- this is the OEM part #

Genuine Denso's are the only one i recommend for replacement other than OEM.

Only replace if your're absolute sure the AF is bad. (usually it is if the code is only in one bank)

Rolodon

Yes all it read was P0171 bank 1 ! I was confused at first when I researched it because of the sensor 1 sensor 2 thing. Only sensors I could locate was the one by the radiator bank 2 , the firewall sensor and one behind the CC so their are only 3 O2 sensors ? I was hoping there was because I've already located them. So you advise against getting a O2 sensor off of eBay? Also can you take these off without a special socket ? Thanks alot

Nad1370

I edited the correct part # for the AF bank 1.
I have a 2000 RX which is the same 1mz motor as your ES.
I was able to use a 7/8" or 22mm wrench just by going underneath the vehicle.
an O2 socket would be sweet.
Something like this:
https://www.partsource.ca/products/o...wrench-crowfit
With your ES, you might get the same luck but by taking the airbox out for access.

Rolodon

Thanks for the part number I'm defiantly gonna check it out. I never thought about going through the top under the air flow in gonna try that. Is there only 3 02 sensors on my car ? I just hope I can get it with a wrench because that's what I got for now. Heck it looks like you should be able too.

LeX2K

Look up the sensors here
http://densoautoparts.com/find-my-part.aspx

Warning there are many fakes out there!