Hi, i have a 2000 dodge neon and the check engine light on. i got p0171 AND the code about the battery being disconnected within 50 starts.(which it hasnt)

symPtoms:

`Car drinks alot of gas, i get about 17 mpg
`car shakes differently, it used to shake even without the light on but i can tell it shakes differently, hard to discribe.
`Car runs great, starts up on first try
`only thing is the mPg and the wierd shaking, it doesnt shake when i am pressing the gas but when idle is when i feel it wierd.
`has 127k mile on it


now, i read it might be the MAF sensor, but does my neon even have that??

Also , my friend said it might be the 02 sensor, is there any way i can easily tell which it is, im not that great with cars.

How much should i Pay to get this diagnosed, whats the goins rate, i am obviously not gonna do it myself, i dont know much

Thanks you!

 

Air filter is fine, needs oil changed in about 2 weeks, spark Plugs were changed in April,

 

muffler seems rusted on the outside, i seen it drip a few drops of water from the side

 

oh, and i had the same codes but they had gone away by themselves like a month ago, and the car was feeling normal, the normal shaking that was always there, but just now i got it back tonight

 

This is my first car btw

 

You don't have a MAF sensor. What you probably have is a vacuum leak. Get looking around for cracked/disconnected vacuum lines and take a look at the accordion tube that connects the air box to the intake manifold. The pleats can form cracks down at the bottom, making them hard to find.

 

Maybe you put a tank of bad gasoline in? like E85?
It is also possible that u got a vacuum leak. I wouldn't randomly throw suspected Sensors on, that's just waste of money.

 

If you are getting a code for the battery being disconnected and it hasn't, you may have a bad ground, an open circuit or just a bad battery.

 

since im getting that battery code, is it Possible that it can be resetting the computer to remove the CEL light by itself?? i dont think so because all the radio stations are still there, wouldnt they be reset if the battery was discconected

 

If the battery is truly disconnected for a few minutes, yes. That's why it could be something else. I don't even get that code when I do disconnect my battery.