Why only 1500 miles? Are you having symptoms of some sort? I'm also wondering if your CAI may be feeding your engine some dirty air -- I don't understand why the lab dismisses ingestion out of hand without more info regarding the non-standard intake. FWIW, I've kept the intake on my G35 straight stock. If your goal is to extract every last possible half-horsepower, maybe, but from my perspective, I get all the power I could want (well, maybe I could want a tad more...) from my car as is. Not to criticise, but on the other hand, it's not as if you've got a gasping 4-cyl and you're trying to make it just respectable.