97 honda civic hx
check engine light came on again today
P0301 misfire detected cylinder 1
P0302 " " cyl. 2
P0303 " " cyl. 3
P0304 " " cyl. 4
P1300 dont know
P1399 manufacture controlled igntion system or misfire (pending code)

The spark plugs are gapped to specifications
The distributor and cap are in excellent shape
The timing is within specifications which is at 13 degrees

Still can't figure it out??? Any ideas???