CHK ENGINE light on. told is OXY Sensor. Where & can replace myself?

I have had this problem myself it turned out to be a blocked exhaust system. Too much back pressure in system blocking the flow causing the power loose

What's your check engine code?

You have a failed transmission, it will need to be torn down and inspected to see exactly what went wrong internally.

could be both oxy and fuel sensors could be poor mix of oxy and fuel or could be rich mix everything everything here 

yes reset by removing fuse or disconnecting battery make sure you have radio code if disconnecting battery. Problem may be oxy sensor in exhaust.

get the catlist converter chk

check you ignition components to see if they are worn or faulty, this is usually the cheapest part that can cause this problem since your tach runs off the ignition.check fuel filter before fuel pump as this could be clogged and also not as expensive as a pump or oxy sensor. a faulty oxy sensor will set a code.

Yes, you can replace them yourself, it's not easy but you will save yourself so much money if you just take the time. Buy a book from your parts store on how to fix your specific vehicle, some wire cutters/stripper and a set of Oxygen sensor sockets. Before doing the work remove the negative battery cable, after your done simply reconnect the battery cable and your codes should automatically remove themselves if you have solved the problem. Good luck!

First thing to remember autozone people ar not experts in the automative diagnostic world, if they were they would be earning 50 - 75,ooo per year as a technician, not 25,000 as a desk jockey. You need to go to a mechanic that has a computer to hookup to your car and tell you what the check engine light is on for. then you can fix the exact problem instead of poking around in the dark at the problem until you get lucky and have it fixed for a week or two,