Something can be goin on with the engine. I have a 1998 Neon and I have a way of getting the trouble shooting codes from the on board computer by using your key. It might not work on the newer Neons but its worth a try. Don't worry it won't harm your car. Ok, with the engine NOT running turn the ignition ON, OFF, ON, OFF, ON. ( must be done within 5 seconds) Make sure the car did'nt start. The check engine light will begin to blink. It will blink the number of the first digit and then pause and will blink the number of the second digit. Example: say the code is 24 the light will blink 2 times, pause, then blink 4 times. I have the codes in repair manual. Get back to me with the code and I'll look it up for you.
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