I have a 2004 Honda Accord V6 that has about 170,000 miles, has had a New Timing Belt and Water Pump installed at 166,000 miles. When I start the car and put the car in Drive, and come to the first stop, after stopping I let off the brake and start to press on the gas and the car acts like its in neutral and won't go, so I have to put it in park then put it in drive again and it will go. It doesn't happen again after that. Any help would be Appreciated.

 

Sounds like a bad transmission. Check the fluid level, color, and if it smells burned. You can try to changing the fluid, this might buy you some time.