How do i know what O2 sensors to order, there are several on my 2002 ford expedition V8/5.4ltr. engine? The diagnostic machine can no longer be used to tell which sensor is down due to my cigarette lighter not working (bad fuse I guess). My error code was previously read as 2 bad 02 sensors, but I cannot find the paperwork with the specific sensors causing the problem.

Hi, I work for Bosch and I run the line that makes the sensors. I have replaced the mine in a 2001 expedition. It's fairly easy, except the driver front. When you go buy your sensor, buy the aftermarket. It has been tested on the line just as the OEM and passed with the same test. The sensors have the exact same components inside the sensor. The auto store will tell you different and so will the shop. The only difference is: when we assemble the OEM, it usually has the OEM marked on it such as Ford, GM, VW and so on. It seems like a long paragraph but I want you and anyone else to understand. However the top of the sensor may look different than the OEM, but that has nothing to do with the function of it. We make what is called LSF which is what yours will probably take. It should have the # marked on it: 0258986602 big aftermarket. This is sold at Advance. Auto Zone. Trust me friend, there's no difference in the OEM and Aftermarket. I wish I knew this when I needed them. Also the OEM is $70-$140+. Aftermarket $35-50. The lighter should not have anything to do with having it checked. Go to Advance, have them do a free check and then buy you sensor while your there. Tip: you may know this but, usually the code for your keypad entry is located under the dash, below the steering wheel. It is usually on a white sticker. It don't state that it is your code but it should be 5 numbers, and this is the master code even if you have changed it to your personal code. Also the **** you here about, we can't make an extra key unless you have 2 extras at the dealership, that is bull. When I bought mine it came with one key and no key fob. I had 2 extra keys made and a fob programmed within 10 min. We have a guy here that is awesome. He does it for the dealerships around here. Sorry for the long paragraph, just want to pass on info for the people that need it.

You will have to fix the lighter and get the code then it wil tell you witch o2 is bad this is a list of locaitons bank 1 sensor 1 is pas side closet to engine / bank 2 sensor 1 is drivers side closest to engine / bank 1 sensor 2 is the sensor before the cat / the bank 1 sensor 3 is after the cat