Good afternoon my name is Tom Brintzenhofe, Certified Master Mechanic out of Reading, PA and today I'm going to talk to you a little bit about how to install oxygen sensors. Now there is a few reasons why you would want to change one. One is increased fuel economy. An oxygen sensor will decrease your gas mileage significantly if they start going bad. Sometimes they will go bad and they won't even set a code and we'll get into that in a little bit but there is a few things you want to look at when you are putting one in. You take the old one out and you want to inspect it for white residue on the outside. That is a good indication that you might have a bad head gasket but the other one might be if you have like I said poor fuel economy, the third one would be if you have a check engine like and if you are a mechanic or if you find out that it's for an 02 sensor. But they're really not that difficult to change or to put in. Once you have it you have got to get yourself an oxy sensor socket and I'll try to explain to you why but you have got these four wires sticking out the top here and in a regular socket you are just not going to get it over top of them. So they made this socket and it is real handy. It just slides down right over top just like this. Lots of wires stick out the side so basically when you get this you find that you just stick it in the hole and then you just tighten it by hand and slide your socket down over top it just to snug it up and I'll show you what I'm talking about here. This one is kind of down underneath here. Then once you get it tightened down all you have got to do is just put your socket on it and then just tighten it right up but that's the easiest way I can tell you how to install an oxygen sensor.