Gas needle went up and down

Gas sloshing around in the tank?

On an '02 Sebring I'm not %100 as I would need to see it for myself to know exactly, But this can be a couple of things, 1. faulty fuel pump unit, the actual pump and pressure regulator itself may be fine but the signals that tell your car where the gas level is could be a bit corroded and when it hits that certain level it may give you a low/no gas message because the corrosion is shorting the power and sending the car's computer a message, it should also have a message if it's hooked up to a scanner, because it's sometimes preprogrammed into the computer to detect a short if it is a shorted out fuel sending unit it shouldn't be difficult to diagnose with a scan tool. 2. On some vehicles the ECU will perform preliminary tests, one of them is a "Sweep" this is just a way for the ECU/BCM/PCM(what have you) to self test the system values and the gauges and self verify that the cluster gauges are operating within the set parameters, it they're not you'll usually be able to check for a stored code and troubleshoot from there. That said, I have seen this on some vehicles pre-2005 that didn't set any codes, they would just blink a check engine light or continue to sweep the gauges, as a signal that something wasn't jiving in the gauges and there was a short/open in the wiring... Mainly what you wanna do is gather information, When did it happen last? What were the conditions? i.e. Was it raining? were you accelerating or braking? Did you do anything new? Is it every other startup? Did you have key on engine off? Did you have key on engine off and pump the gas/brake pedal? Is there anything aftermarket you added recently? Document this type of stuff, the reason being when someone brings a car in with a problem that isn't something that happens all the time and hasn't set any type of codes it's like a wild goose chase and can cost the car owner the price of an inspection, especially when it may be something in the system like the gauge sweeps I mentioned above! :)