2002 Nissan Sentra 4th cylinder misfire detected

Hi. I have a '02 Nissan Sentra GXE and it runs perfect. But every time I start the engine in the morning, the engine vibrates but it stops vibrating after it warms up. When I pull the gas wire to rev the engine, I hear a fizzy sound (like pop rocks in your mouth) from the 4th cylinder, I'm not sure if it's the ignition coil or inside the cylinder itself. I already put new spark plugs, changed oil and oil filter, and put a Lucas fuel injector cleaner. I scanned the car and this came out:

4th cylinder misfire detected. Probable cause

1. Ignition system fault
2. Fuel system fault
3. Vacuum leak affecting on cylinder
4. Engine mechanical condition

Thank you so much for the help, I appreciate it!