Rough idle and loss of power with codes p1344 and p1350 (mysfires)

[jac]

I would appreciate your guidance on troubleshooting this.

I did a bit of reading through some old threads, and also based solely on the direct meaning of the codes, I am thinking I should (in no particular order):

- check the ignition coils and spark plugs (cylinders 2 and 5) --- but I doubt this is going to be the problem since all 6 coils and spark plugs are 1.5 years old or so
- do a vacuum leak test

Am I on the right track?

Thanks!