Plugs? Coil packs? What engine? Nothing you replaced deals with the ignition system. The shaking is probably from one or more cylinders not firing. I'd be checking the ignition system for a misfire code.

 

Well I didn't realize there was an ignition problem. I was just told that I needed to replace everything else

 

Sounds like the guy/that shop might be taking you for all the $$$ they can get. Throwing parts at an issue can be very expensive and fruitless. That's why you need to get the code read.

 

Start off by never going to Pep Boys again. Firestone can be hit or miss. Find a local shop with someone worth a damn or go to the dealer, even if just for a correct diagnosis.

I'm not sure who told you "your tires could fall off" or what a tire sensor is or how it keeps your tires on, but don't go back to that person, especially if it was Pep Boys.

You need someone who knows how a car/truck actually works to read your code and look for a misfire and diagnose it.