im cam, a licenced diagnostic tech.
these codes are for two different systems.
we'll start with the p1443...
this is for the evap system.
i have replace quite a few canister vent solenoids for this. this valve should hold vacuum when energized and fully release when commanded.
a smoke machine is the proper way to check evap system problems but manually checking valves is just as effective when one is not available.
the p0304 and p0303 codes are misfire codes for those 2 cylinders.
you have done the correct repairs to try and fix these codes.
I noticed that you replaced the coil pack. I would recommend swapping the 2 coil packs and clearing the codes and seeing if the same codes come back, as ive seen bad coil pack right out of the box. if there are different cylinder codes than the new coil pack was defective.
if its the same codes, than a compression test in all cylinders are necassary to eliminate engine mechanical problem.
compare cylinders 1 and 2 to 3 and 4. also attach a vacuum gauge while the engine is running and watch for the gauge rocking back and forth. this will also show a valve problem. But i would start with the coil swap first to eliminate a bad coil.
let me know what you find out