2009 Mazda 3i Manual O2 Sensor?
 

I have been fighting with this for almost two weeks.

A bank 1 sensor 1 OBD popped, so I found this part:

https://www.autopartswarehouse.com/s...EPM960920.html

"Guaranteed" to fit my car.

It does not fit my car.

That part is for an upstream/before catalytic converter O2 sensor so I have no idea why it doesn't fit, unless I have a 5 wire. I don't have the car here to look.

How do I tell if I have a 4 wire or a 5 wire? EVERY car parts place I'm talking to is insisting this part will fit, when it simply does not. Unfortunately my husband had to get to work so don't have the car to look, so I was hoping that there was some other way to know. We looked online and cross-checked several sites/videos/pictures to make sure he was actually replacing the correct sensor. It's the one not hiding on the other side of the engine and is relatively easy to get to.

It's a 2009 Mazda 3i F VIN manual. ANY help would be appreciated.