Why Did My Z, Keep Revving? Video.

ChrisSlicks

With the throttle cut feature on the Infiniti and our Nissans, you do have to press the brake reasonably firmly. With the brake pressed the throttle input is cut back (but not cut completely) if the throttle input is moderate to high. If the throttle input is light then it will let you press both pedals at the same time and wont interfere.

As it doesn't take a lot of throttle input to rev to 4500 rpm unloaded (out of gear) I'm guessing that the throttle input signal wasn't high enough to warrant a throttle cut. Even with a throttle cut you would feel the car pull on you a little as you braked but it would be easy to overcome by braking firmly.

Would be interesting to see what voltage the APPS (accelerator pedal position sensor) is sending out in the misbehaving case. From that you could determine if it was a bad sensor or if the ECU needs to recalibrate a new up-pedal voltage. Bad sensors are rare because they do send out 2 redundant signals. It could be that the dealer screwed up the calibration by disconnecting the harness when you took it in for something else. I'll check if the car sends out throttle position or voltage as and available data point on the OBDII/CAN.