2001 Chevrolet Cavalier Car problem

The throttle position sensor won't cause a single cylinder misfire. At most it will cause a slight hesitation on acceleration.

Since the spark plugs were replaced recently, that's the first place to look. Check if they're gapped correctly and that a ceramic insulator isn't broken and fallen down, blocking the electrode. That can happen if one is dropped.

Other things to consider are a defective injector, low compression, and a worn lobe on the camshaft. Try switching two injectors to see if the misfire switches to a different cylinder.