2004 s430 engine starts but will not go into drive does anyone have an idea why

 

could be a bad brake light switch but usually its a shifter problem. bang the top of the shifter with a rubber mallet as you try to pull it out of park and it will come out of gear

 

It could be the infamous broken plastic part that locks gear in park until you press brake. If it is the broken part, the mallet maneuver will get you out of park a few times then it wont work anymore. Search for "stuck in park" in the threads and on you-tube. There is a lot of information on fixing it yourself, or take it to your mechanic who will just replace the whole shift unit for upwards of $1200 to $1800.