I am a little confused ok a lot!!! I am thinking on replacing the front o2 sensor, ok they have so many types most are splice in, my book tells me there is a difference from the upstream and downstream, the one the sell aftermarket don't, plus some are 4 wire and others a 1 wire, I want to replace the front upsteam I think it is a 3 wire. what do I do ? other then buy it from Kia which wants a few fingers for it, I have a 2001.

I ordered from kia @ about $80.00 each a while back. It turned out that all I had to do was spray some electrical cleaner/degreaser on the wire connectors for the second bank <img src="/forums/images/graemlins/confused.gif" alt="" /> But it is imperative to get the bank 0ne changed if needed. <img src="/forums/images/graemlins/kewl.gif" alt="" />

[color:"green"]check your kia oxygen sensor if it really needs a replacement.. you can try to grease or clean up your sensors, but if it is defected or broken it would be best to have it changed. [/color]

I replace the upstream then a week or 2 the down stream went. it has 106000 miles and I see it things go bad after 100000, gee maybe thats why new cars give 10year 100000 mile sounds great when you buy new <img src="/forums/images/graemlins/kewl.gif" alt="" /> but come to the 100000 and the dealer tells you it's up now to repair it will only cost you money just like the song, then you go from <img src="/forums/images/graemlins/kewl.gif" alt="" /> to this <img src="/forums/images/graemlins/scared.gif" alt="" />then this <img src="/forums/images/graemlins/angry.gif" alt="" />tyhen this to the dealer <img src="/forums/images/graemlins/butwiggle.gif" alt="" /> LOL

Now you catching on!!! <img src="/forums/images/graemlins/lol.gif" alt="" />

Yep!!!! <img src="/forums/images/graemlins/lol.gif" alt="" />

Both O2 sensors are 4 wire. One wire sensors will NOT work. And yes, the front and rear are different part numbers. Some have had good luck using universal 4 wire O2 sensors in both locations. You can roll the dice and try it and if it doesn't work use a factory original part.