I would be concerned about warranty claims if you had headers. I suppose you could switch them back if there's problem before going to the dealer. That would be a real hassle but in the case of any Acura probably not a very likely scenario (having a serious problem, that is).
I always used K&N s in my vehicles, but that is not a big hp gain by any means. The way engines are engineered these days, I don't believe you get a whole lot more out of them although exhaust is the usual way to get some since there is some compromise in the interest of reducing noise. But when you see how many newer cars have 'duals' and 2 way mufflers (Maxima) in the interest of providing a bit more go when there's high demand for power, they are addressing that to some extent too.
You know the old saying, 'there is no substitute for cubic inches'.. so maybe a 2003?
I always used K&N s in my vehicles, but that is not a big hp gain by any means. The way engines are engineered these days, I don't believe you get a whole lot more out of them although exhaust is the usual way to get some since there is some compromise in the interest of reducing noise. But when you see how many newer cars have 'duals' and 2 way mufflers (Maxima) in the interest of providing a bit more go when there's high demand for power, they are addressing that to some extent too.
You know the old saying, 'there is no substitute for cubic inches'.. so maybe a 2003?