If you know this is a "misfire" then you need to isolate which cylinder is misfiring. Once uou have done this the only items in the sequence would be the plug, wire, if this model has separate coils, the coil. If it has a distributor, the distributor cap and rotor. If it is electronic fuel injection, it is possible the injector is bad which would effect performance, but don't know if you would notice it as a misfire.

Unfortunately I can't seem to open your photo to view it properly.
Have a look on the following link which explains about the error code you have:

http://www.obd-codes.com/p0316

There's also more information on
mazda p0316 error code Google Search Read about it first. The more information you have to hand will assist in locating the fault