Sometimes it doesn't cost anything to fix this problem. Surprised autozone didn't sell you a new sensor, perhaps they didn't know which one. Any work been done to car recently?
We can help you with this. Once we give an answer you'll have to pay the deposit before you can read the answer. If you don't pay the deposit you'll never see the answer. As a sign a good faith go ahead and pay the deposit and "help is on the way".
And please include vehicle make, model, year, engine, etc (anything relevant).