O2 sensors

They are different.

I just looked up "02 Sensors" for your specific vehicle at two popular auto parts store's online sites.

They have different part numbers, it was listed beside them as to which location they belong.

Hope this helps you!

Along with that, this might also help out, you will have to do a little homework to update the information so that will currently work the best for you (codes have changed since I gave this answer). The system still works well, as I saved $41.00 off of a $125.00 battery two weeks ago. See my link.

http://www.2carpros.com/questions/2001-dodge-neon-milage-just-want-put-fliuds-their-locations

Let us know how it is working out!

The Medic