I just got a 2004 infiniti g35 sedan. Awd. My girlfriend wanted a new accord and I talked her out of it for this one. She loves the way it looks and drives. BUT... It seems to have some issues. Here's the rundown. Car had no check engine light when bought it. We've only out maybe 400 miles on it. The car seems to hesitate shifting around 35-40 mph. Then when at around 70 it's taching about 4500 rpm. Sounds like would blow up is ran 80-90. I put over to manual shift and it says its in fourth. I shift to fifth and no change in sound. Then go back to drive. If go back it always shows only in fourth gear. When first was doing it I read about can sensor causing similar problems. I replaced it but no change. Then the check engine light came on. Only code is for oxygen sensor then. I then was told maybe throttle position sensor. So I got a whole throttle body and replaced it. No change. Tried to do a reset of tps and still nothing different. Have heard crank sensor could cause issues or the gas pedal sensor. Haven't replaced either. But don't want to keep throwing parts for nothing. Took to autozone today and he got here codes. Said was showing the transmission sensor and something else about air flow and engine not reading something. I'm just hoping someone on here has had similar issues or knows what to look for or maybe some way to check so I don't keep guessing. My girlfriend loves the car but she's getting ready to dump it. And really can't afford a new car. Someone please help. Also if it is the tcm is it located in tranny pan or under kick panel. I've heard both on 2004.