I had a customer with a 2002 Infiniti I35 with a problem. The car would just stop accelerating while driving and go into idle. If you let it rest a few minutes and it would be OK for several more miles. If you cleared the fault codes on the engine ECU it would be OK for about 100 miles. But after this 100 miles it would continue to have this same loss of power problem. I tried changing many different components. I changed the throttle body, MAF, electronic power control (the accelerator pedal), spark plugs, VIAS solenoid, and a few other parts. I tightened all the electrical connections especially the grounds. I checked to make sure all electrical components had a good connection. Still, I could not fix the problem. The customer was tired of spending money and not having any good results. Several months down the road the Infiniti just plain stopped running all together. It died in the middle of the road. But this actually turned out to be a good thing. Because finally I was able to diagnose the original problem. The battery was totally dead. The alternator had stopped charging and was bad. This alternator problem turned out to be the answer to the loss of power problem all along. I was stumped because usually when an alternator goes bad, the battery gets drained of all of its power. The dead battery is always how you diagnose a bad alternator. But in the case of this Infiniti, the alternator was good enough to charge the battery but not keep the car running properly. You learn something new everyday. Max