ok so i have an 01 maxima se....20th ann. 5 speed. i've been having some problems the past 2 weeks. my car gets up to about 3800, 4000 rpms and either hesitates for a while, or just stay right at 4000 and feels like its red line-ing. its lost a huge amount of power. it idles fine and runs fine up to 3000 rpm. no check engine light came on or anything, but i hooked up a code reader anyway, it first came up with an ignition signal code....then later it came up that cylinder 5 was misfiring. so i thought yes this is the problem. i replaced the spark plug and coil but the problem is still occuring. i am no longer picking up a misfire on the code reader tho. i tried resetting the ecu but nothing is working. i dont know what else it could be. i did have an aftermarket short ram intake on it but i had it on for a while before this happened. i put the stock intake back on anyway and i figured if my MAF sensor was bad the check engine light would deff be on. if anyone could help me it would be greatly appriciated.