Repairing a 1999 Volvo S70 turbo with error code P0455, P0305, P0301 & P1550

A client brought me a 1999 Volvo S70 station wagon that had engine problems. I noticed immediately that the “Check Engine” light was on. I got my OBD2 code reader and got the following codes. 

P0455 - EVAP emission control leak (large)

P0305 - Misfire cylinder #5

P0301 - Misfire cylinder #1

P1550 - Faulty ABS module

I checked the EVAP tube that is connected to the intake manifold to the gas tank and found it ripped. I replaced that and that took care of the P0455 error code. 

When I reset the system, the P1550 did not come back and so I guess the ABS control module is fine. 

For the P0301 & P0305, I did the following:

1. Did a visual inspection on the wires connecting to the ignition coils of each spark plug to see if there are any damage, cracks or burned areas. I did not find any.
2. I pulled out each ignition coil and check for damage, cracks or burned areas--found none
3. Check the spark plugs. They seemed ok. 
4. I check the compression on each 5 cylinder and it registered about 183 PSI. Seemed normal.
5. I put back the spark plugs, ignition coil and started the engine. I check each fuel injector if it has damage. None
6. I check the wires going to each injector. No damage. 
7. Using a long screw driver, I placed the tip of the screw driver on the bottom of each injector while the engine was running and listen for a clicking sound to find out if the mechanism inside is working. All 5 injectors seemed working. 
8. I cleaned the tips of the spark plugs on cylinder #1 & #2 then swapped the spark plugs. For some reason, that took care of P0301. 
9. I swapped the ignition coil of cylinder #4 to cylinder#5. I reset the system and drove the car for 10 miles. The check engine light went back on. When I checked it, the error code went from P0305 to P0304. I immediately knew that the ignition coil is bad.  After the bought a new ignition coil, the Volvo started working fine.