My daughter was preparing to leave for college on tuesday and her grand prix stopped going in reverse and kicked a p0741 code. Can antone help me troubleshoot this please? She is supposed to be driving her car across the country ina. Couple days and this has me really concerned. It drives we'll in all other gears. I did notice slight shinning at low rpm when going up a hill when I test drove it. Other then that it runs well. Transmission fluid is full and looks good. She just had it changed 2 summers ago and she only drives the car for 3 months in the summer each year since. When I shift it into reverse I can feel it click in just like normal but it doesn't move when I hit the gas. I assume I need to check the wiring and the TCC solenoid first but I'm not sure beyond that. Car has 160,000 miles.

I forgot to mention this has the base v6 in it.

Thanks

P0420 = Catalyst low efficiency (this is not your problem, but can be if the car has the great luck of needing emissions checks)

This would probably be repaired just by replacing the catalytic converter.

P0741 = Torque converter vs. transmission input shaft speeds more than 200RPM difference when lockup is expected

This tells me that the torque converter clutch is not locking when it is expected to. This could be due to a number of issues. The first things I'll ask:

Is the transmission the original one that the factory put in the car as far as you know?

When the fluid was changed two summers ago, was the filter changed and the pan cleaned at the same time?

What is the current level of the transmission fluid when after the car has been driven at least 20 minutes and left idling for two minutes?