Jb4 misfire cylinder 2

I installed a jb4 on my car a week or so ago, new ngk spark plugs from n75 about a month ago, and since installing the jb4 I've had 2 misfire codes while idling, both for second cylinder. First time it happened I gapped my plugs down to .022 and moved a ignition coil over, cleared the code with jb4. Misfire code popped back up again today while idling for the same cylinder but now I also have a p0300 code. What should my next steps be?