wow i've read about this problem (sluggish performance) in so many forums and i didn't find a solid solution to this. some people fixed it by replacing the CAM position sensor but most of them got the problem back after couple of weeks. some changed the spark plugs, battery (in the case of above, which is really weird), dirty throttle or MAF, and ...
now in my case, i scanned my car last week and i got two errors
1) something related to throttle controller being dirty or something
2) cylinder 4-6 mixing something
i knew i had a bad valve cover gasket since it was leaking so i changed it this past weekend, it was an easy job and kinda fun
. next day CEL went off and car was much better. yesterday going back home from work it came back on and the performance was horrible, it was like a 316. now today coming to work it's much better. i'm really pissed, why this car behaves likes this arghhhhhhhhhhh. some days its just running awesome (25% of the time) and other times its just close to normal or bad performance. i'll keep you guys posted if i got this problem out of the way once in for all.