Hi, Yes, this part fits both the upstream and downstream. Basically it is interchangeable.

Hi Zachary, I'm glad to assist you. To check if these are the correct sensors, use our vehicle selector. Make sure to enter the exact year, make, submodel, and engine size. Our website will automatically inform you if the part is a guaranteed fit for the selected vehicle. I hope this helps, and happy shopping.

Hi Bradley, thank you for reaching out. Kindly call our parts team at 1-866-529-0412, so we can help you look for the correct oxygen sensors base on your complete vehicle information. Have a nice day.

Hi Jorge, I'm happy to assist you. This item fits the 2001 Toyota Highlander with a 4 cylinder 2.4 liter engine, but not the V6 3.0 liter engine. You can use this link to go back to the item page and continue the order: https://www.carparts.com/oxygen-sensor/drivewire/set-arbl960901-2?can=CPAP3648 I hope this helps. Enjoy shopping at Carparts.com!

Hi Eric, Please enter the code generated by the scan tool on the website link below So you would be able to see what part is malfunctioning or having issues. Or refer to a trusted vehicle specific repair manual. I cannot be of help to you right now since you did not provide the code that came up on the scan tool diagnostic. https://www.obd-codes.com/ Then, look up the oxygen sensor upstream or downstream bank 1 or 2 from our homepage. Please follow the steps below. On the homepage, please enter your application, simply select your vehicle’s year, make, model, sub-model, and engine size and click “Go.” Once your application is selected, type the name of the part you need on the top search box and press enter. Once the part shows up on your screen, you’ll see a “Guaranteed to Fit, Direct fit” note/badge if the part will fit, and we recommend that you also double-check your vehicle fit details as well as the vehicle fitment information table on the product page.