[rjitzsu]

does the vehicle only exhibit the misfire when coming to a stop or after driving and then slowing down?

if so, odds are your egr valve is hanging open. there was an issue with the vehicle in which the egr valve would rust along the shaft and it would thus stick open allowing exhaust gas to enter the combustion chamber at idle.

the way to determine if this is the case, primarily, is to identify when it happens. egr will never open fully at idle. it should only open at cruise speeds and steady throttle. if you are willing to do so a simple complain description at your local mazda dealer should lead them to test your egr stepper motor and monitor your baro sensor readings while doing so.

if the car only stumbles after some driving and while coming to a stop this is most likely your problem. while i have seen many many other similar problems with this car this may be your best guess... so... either drop the 90 bucks at your mazda dealer to have it diagnosed or throw the 200 dollar part at it. your call...

hope this helps a bit.
good luck.