O2 Sensors

EDieter · Post by **EDieter** » Thu Apr 19, 2012 5:53 pm

Does a 2002 SXT use the same 02 sensor in both banks?

The reason I ask this is because after getting ym O2 Sensors replaced and putting in a wideband for a/f ratio the mechanic MIGHT have put a upstream in my downstream bank. I think this because the O2 sensors I brought with me to have replaced I had explained which was which to him. Come to find out one of the O2 Sensors (downstream) wasn't the one I needed, Autozone made a mistake and put a completely wrong sensor in the box (the connector was rectangular and not circular). So the mechanic told me this and said that I need to go get the real UPSTREAM sensor because the other sensor he put in ym downstream. When I got to autozone I find out that the part number that had an empty box because the mechanic put that o2 sensor in my downstream was an upstream sensor. so i figured ok i have an upstream i need to get a downstream, ill bring it back to the mechanic and have him put them in the RIGHT place. The mechanic ended up just putting the downstream I bought the second time around in my upstream saying that 2002 sxt's use the same sensor in both banks, the bank just determines what that sensor is going to do, but they can be switched. I don't know if I trust him so I want to find out from yall.

r/tguy02 · Post by **r/tguy02** » Fri Apr 20, 2012 8:00 am

they're different, and so long as they came with factory plugs it is impossible to interchange them. if they were the universal type you have to splice in, i suppose it is possible to get them backwards...

Dranz · Post by **Dranz** » Fri Apr 20, 2012 8:45 am

If they were universal it wouldn't matter where you put them anyway...

EDieter · Post by **EDieter** » Fri Apr 20, 2012 8:58 am

Wait what? Bosch makes a universal kit, the smartlink, where you cut the wires to length and fit the plug together, but the ones I purchased where not labeled universal, they were labeled O.E.M. fit. Maybe I wasn't clear with ym question, basically if I went out to my car right now and decided to switch my O2 sensors, ie: take my current upstream and put it in my downstream and take my downstream and put it in my upstream, would I screw anything up?

I've looked into what the sensors are and both are narrowband heated, the only difference I can find is one is labeled upstream and one downstream. I know the upstream is to help the car determine a/f ratio, and the downstream is to determine if the catalytic converter is working properly. BUT is that a function relative to the location of the o2 sensor, or function relative to the actual O2 sensor. (would a downstream still try to determine catalytic performance in the upstream bank, or the computer would know to use the information being sent for a/f ratio?)

r/tguy02 · Post by **r/tguy02** » Fri Apr 20, 2012 9:13 am

if they're oem style then no you wouldnt be able to switch them, they have different plugs

EDieter · Post by **EDieter** » Fri Apr 20, 2012 9:25 am

wow...you are right... the downstream sensor's bottom notch in the plug is only offset a tiny bit and I didn't notice that. Thanks for helping me realize this... im gonna go find a concrete wall to bang my head on

Donkeypuncher · Post by **Donkeypuncher** » Sat Apr 21, 2012 9:58 am

I believe the actual sensor itself is different, not just the plug.

gilly02le · Post by **gilly02le** » Sat Apr 21, 2012 6:03 pm

the downstream sensor has more shielding on the sensor probe to protect it from moisture produced by the cat, electronically, they are the same.