O2 Sensor

[Rust_Bucket]

Hey all. Was hoping one of you could point me in the right direction with what part to order...

Bracket and wires from center bottom of Jeep. Wires run from the cat to the o2 sensor. Looking up parts right now and I would assume that I need to replace my o2 sensor "upstream?" Please ask questions if this doesn't make sense.

Here's the story: Jeep has been running fairly rich and has a random hiccup every so often at freeway speeds, as if I have a misfire. Engine light is on, and o2 sensor is quite obviously disconnected as I dragged the wires and bracket for about a mile until I looked under and saw the severed wires. The bracket seems to be alright.

Looking at a catalog I have these options:

Oxygen Sensor Downstream
Oxygen Sensor Front
Oxygen Sensor Rear
Oxygen Sensor Upstream

I don't want to make a brash decision, and this is my first time doing a sensor. Please help!

RB

 

[Crouse11c]

Well depending on model and year you might have both up and down, which is before cat and one after. Or you could have 2 before and 2 after the cat. With out more info would be hard to say. But my best guess would be downstream or after the cat because it would be closer to the ground (you said it was dragging) in most cases. Most auto stores have very nice employees (napa, autozone) that will come out and look at it for you so you can order the right part and if it can be check via their computer can tell you what the error code is that is setting off engine light also.

 

[saar]

Hi,

As far as I understood, if you have 2 cat's then you have 4 O2 sensors, otherwise, you have 2.
That is what the support at rock auto told me when I replaced my O2 sensors.
Saar.

 

[jimbob2001]

Hi. All ! Been a. While. Since last. Post - but. Now back. I. Believe. Previous. Post is. Correct. Only. 4. O2. Sensors. - If. You have. 2. CATS. Anyway, you mentioned. Your. Engine. LITE. Was. ON. Did you. Dump. The. Codes?? This. Can be done a couple of. Ways: 1. Cycle. IGN. Key. ON/OFF three. Times. - On. 4th. Time. You turn. Key. ON. - Codes will. Appear. Where. Your. Odometer is. 2. Take. Car. To. - AUTOZONE. - - Or. Parts. DLR. - They. Can. Access. The. Codes. 3. Buy a. - - CAR. MD. - this. Way. You can. CHK. YOUR. CODES. All. Cars. After. 1996. Have the. - OBD. Port. - - To. Access. CHK. ENG. Codes- Good. Luck!