2000 Sebring Convertible won't start
 

My daughters started the car the other day and it started but was shaking. It made it about 20 feet and she shut it off. I came up there and started on the 4th try and it sounded normal. I drove it about 30 ft and it started to shake(the engine was running rough) and the car had little reponse to the gas pedal. It finally stalled and I have not been able to start it since. I read the fault code with an OBD II and it had a P0171 fault which calls out an O2 sensor but everyone I talk to says that that wont cause it not to start. I have spark and fuel to the engine. when I was checking the spark plugs I noticed that the plugs were soaked in oil which was caused by the valve cover gasket leaking so I replaced them and the valve cover gasket. The intake cover looked black which I assumed was from the burning oil from the leaking oil from the spark plugs. Anybody with any ideas my daughter is starting her senior year riding the bus which is funny to me not to her.

P0171 indicates the system is running lean. Could be a plugged or defective injector or a vacuum leak.

How do I find a vacuum leak? or check the fuel injectors? Thanks.

You search for a vacuum leak with a piece of tubing. Hold one end close to your ear, search every possible vacuum connection/tube/hose etc. with the other end, listen for a hissing noise. But of course, you can't do this if the car is not running
You might have some luck cleaning the fuel injectors with an additive dumped into the gas tank. Again, you need a running engine for this to work. If further servicing is necessary, you have to remove the injectors, which requires removal of the upper intake manifold (V6) or at least the throttle body (4 cyl).
If the car won't start at all, there's probably something else going on though. Check for fuel pressure, spark. Check ASD relay. Browse around the forum here to see what others have done for a similar problem.