Trouble Code P1133

I went to Auto Zone and had them to do scan on my 98 cavalier 2.2L

It came up a P113- HO2S/O2S insufficient switching senor 1 (is that right??)

What part will I need to buy? And how to replace it?

Try replacing the upstream o2 sensor, should be around $20. It's on your exhaust manifold/header.