Hello,

I have 2001 Camry Le automatic 4 cylinder gas engine and I got a code to change my upstream (Bank 1) only. No code for downstream. Should I replace both regardless because they work coherently together? I have a feeling that if I only replace the upstream one to clear the code, sooner or later it's gonna send a faulty code for the downstream one because that sensor can't keep up with the newer sensor readings. Thanks a lot.

 

Not really required.

The sensors are not mated to each other. They operate independently. Can change one or the other and not have an issue.

The downstream fails much less frequent then upstream.

Upstream sensor performance effects engine performance (very important). Downstream is there to monitor emissions converter performance.

If changing sensors suggest Toyota brand or Denso brand.

 

Understood. Also the part number on the current one doesn't make sense compared to what I'm finding online. The current upstream sensor has a part number of 192400-8030 04S13 Denso on it which i can't find anywhere online. While the one i need from research is actually Denso #234-4626 without the California emissions. Is the current one I have on an old OEM part? Because I can't even find google it with any results.