What cause misfire on cylinder #3 & #4?

what cause misfire on #3 and #4 cylinder I replace #3 coil no change made I check for pulse at 3 and 4 injector with a noid light the light flash and injectors are clicking.engine codes are P0300, P0303, P0304. compression #1, cylinder 195psi, cylinder #2, 190psi cylinder #3, 185psi, cylinder #4, 190psi.

Good job checking the compression, lets remove the spark plugs for inspection. We need to see what color they are so we know in what direction to go in the make the repair. The fuel injectors maybe getting a signal but if the injectors are bad/clogged it wont make a difference. Please unload images of the spark plugs so I can see them. Also here is a guide and video which can help in the meantime.

https://www.youtube.com/watch?v=QTE8k06MzwQ

and

https://www.2carpros.com/articles/engine-misfires-or-runs-rough/

Please go over these guides and get back to us.

You may have a PCM that is bad, lets check the injector pulse and power feed, this guide will show you how.

https://www.2carpros.com/articles/how-to-test-a-fuel-injector/

You should have 12 volts on one of the injector feed wires for each injector . Let us know how it goes

12 volts at the injector feed wire with key on

That is a good sign, did you go over the guide above to check the injector pulse?

yes i went over the guide. i have injectors pulse but sometime on injector #3 my noid start blinking and then stop and start back.