i dont know the firing order off the top of my head but if you look at the engine on the rear bank (firewall) from the left is 1,3,5. on the front from the left if is 2,4,6. Hope that helps.
The problem that occurs is when the CX-7's and ('s sit on the lot for awhile. I have personally had to machine the rotors on many new cars. It is caused by the vehicles staying stationary in one spot for long periods of time. The rotors then continue to build up rust on the parts of the rotor...
I am thinking that your intake manifold gasket is leaking on the bottom of the manifold. It breaks underneath sometimes and you sometimes cant see it. It may be worth doing it if you have alot of miles as it is pretty cheap at the dealer.
I just came back form a Mazda QMD meeting today and this was discussed. Mazda did a change to the pistons and rings in later models to help combat this problem but what you can do is change to 5w30. The oil may change your fuel economy slightlt but 5w20 was tested for the emissions. 5w30 is...