Injector fault code p204

[smccabe12]

I have a 2010 pro xs optimax 200, serial #1B805431. 243 hours. I recently noticed I dropped a couple of mphs on my top speed. Then noticed it idling a little rougher than usual. Pulled all the plugs and replaced. Cylinder 2 was fouled pretty bad and cylinder 4 was fouled too but not as bad. The #2 coil pack and wire appeared to have a bad connection so I replaced that coil pack and all the wires. Took it out and it ran the same today. Checked codes with vessel view and it set a 204-1 today. It never set a code in the past. Took it to a local shop. Tech scanned it and ohmed out the injector and harness and said everything seemed fine. We put another injector in to see if that would fix it. Took it back out. Seems to run a little better but still doesn't seem 100%. My top speed seems down slightly but it sounds perfect when running 5400. It did not set the p204-1 code again. Is there any other test I can have done or do my self. I just dont want to cause any damage. It just frustrating because I'm not sure if the tide, wind, load are making me run slower or if it's something wrong.

[EuropeanAM]

Cylinder Misfire Test (on the water).

Did you replace the plugs?

[smccabe12]

Yes I replaced the plugs

[EuropeanAM]

Just to clarify: You replaced them AFTER the injector was replaced, correct?

[smccabe12]

I replaced the plugs and wires before the injector was replaced. But I only fired up the motor for like 5 minutes before I put the boat on the trailer and took it to the shop where they swapped out the #4 injector.

[EuropeanAM]

I'd suggest getting it on the water with a tech for a Cylinder Misfire Test at higher RPM's.

Also- did you use an OEM Mercury/Quicksilver coil?