P0300 code went away after change fuel filter, why is it still idling rough? on 2004 Chevrolet Cavalier

I had a P0300 multi misfire code, I changed the spark plugs, wire set, fuel filter, air filter and cleaned the throttle body and the code went away, but is still idling rough and stalling when I come to a stop sign. I checked the fuel pressure and that is running normal. I then checked the vacuum lines for leaks and found none. I am not sure where to turn next.

What are you calling a wire set, the plug boots? Code went away??
2 more answers , 2 more comments
you may have an injectore issue or worse, seek a diag by a good mech in your area
You're missing something; Take it to a technician who does drivability diagnostics. Sounds like it's above your head, and something we deal with daily. Sounds like you still have a vacuum leak, but I can't say what single thing is causing your problem without testing it first.
Thank you, but it is nothing above my head that I cannot fix. As long as I can diagnose the problem, I can fix the problem. I am not trying to sound mean at all. I just am trying to get a good sense of direction to go in next, due to that I do not have money to play around with, nor the money to take the car to someone.
Not being mean at all; Just do you have the equipment to test further. It needs to be smoked to determine gasket leaks, it needs to have data ran on a diagnostic tool, to determine the sensor perimeters it is operating in and if there is a fault causing your problems. I didn't mean to run you down or want to say you don't have any knowledge. Just figured you don't have the right tools to fix your problem. The money you spent was good maintenance for the car, but it is still not fixed, that's why we are both here. There's your information and sorry you misunderstood. Good Day