Ok so i have an 04 maxima that is stuck in fail safe mode, i have read plenty of threads about this and have yet found one that relates to mine. It started about 4 months ago and since it has started it has yet to throw an engine or tranny light. I have my own scanner and scanned it regardless and it does not show any codes. I started reading about the MAF sensor, Cam sensors, Knock sensor. I unplugged the MAF and plugged it back in and that fixed it for a day then came back. I decided to replace it and it fixed it for maybe 2 days, i warrentied the sensor and problem was still there. I then decided to replace other sensors, (both cams, knock, crank). That again worked for about 3 days then the problem returned. Im usually good about dianosing cars but this one has me stumped. The car would occasionally be fine but the past 2 weeks has been stuck in fifth gear for good. The main thing is i dont have any codes to get me in any direction. Im hoping someone out there has had this issue and can maybe point me in the right direction. PLEASE HELP...