Thst is funny you mention your problem. Last week we had a 5spd 02 altima come in. The complaint was the vehicle would not accelerate above 1500 rpms. Well upon inspection my A tech noticed a couple of bolts missing from air box and one from Mass Air flow sensor. Using nissan's consult we found out MAS was bad an needed replacement. Cust stated that he took the intake apart to see if there was a problem. Well its a shame he had to pay $600. bucks for a mass air flow because nissan corp declined responsibilty. Good thing you put it back together properly cause you would have had to pay for it. This guy had customer exhaust and a few other goodies. I felt bad. Oh well.