I have a 2005 Premacy that has developed a mid range stutter or hesitation. 150k and regularly serviced, though by a local mechanic, not a Mazda dealer. It threw a fault a week ago, P2177, which I have cleared and not reoccured. Have replaced plugs, removed and cleaned the intake manifold, including the PCV valve and MAP/MAF and IAT. Coils have been tested as ok by autoelectrian. Visually checked what I can and haven't found anything obviously amiss. Borrowed a decent scan tool and a test drive hasn't shown any faults. However, the issue remains. Car drives fine under 3500 rpm, and switching to manual seems easier to drive past the hesitation. After around 5500 rpm everything frees up again. Catylitic converter is potentially needing replacement (sometimes a gunpowder smell) but this comes on suddenly so I don't think it is the cause. The car hangs onto second a bit longer that it should, and the other odd thing is the car seems to run quite cool, will at times reach mid temp range but will drift back down to cool while driving. This seems to be a reasonably common Mazda issue, but not sure if the Mazda 3/6 recommendations apply to the Premacy.