I have a 2000 chrysler neon i put a flow threw exaust on it. this problem was going on before, to there is a hesatation on take off and chugging when driveing i replaced the coil pack and plugs and wires don't know what this can be

Did you check two things 1) wheel bearings 2) break pads?

Could be one of these things:
Dodgy exhaust sensor. Dodgy Timing Belt. Kanckered EMS (expensive!!!)

At worst you could have a dodgy solanoid in the auto box (this is what happened to mine) and that'll eventually put the car into "limp" mode - meaning no reverse gear and gears 1-3 only with max speed of around 54 mph (usually accompanied by flashing engine management warning light in amber). This set me back almost a grand to strip out the auto box and refurb it. The car has never been the same since either - it's ok but slower to change gear than ever before.
If the gearbox has a fault I would recommend ditching the car - it isn't worth fixing as the cost is roughly equal to the value of the car if it has a low mileage. If the mileage is above 100,000 you'd be lucky to get 1000 quid for the motor in the first place.
Sorry.

Hello
My son races a neon on dirt fast car!=srt mopar stage 3 turbo kit,,, 3" exaust etc,,,
I would just remove tha airbages from the car there flamable if for some reason you have a fire they will go off even not conected.
drivers just unbolts from the wheel 4 10 mm bolts
pasanger bag have to go threw the glove box again 4 10 mm bolts
let me know if i can help more

mass air flow sencer and idle sencer

There are several ways about this. Could be fuel filter, water in fuel, ignition part starting to fail(plug, wire, cap, rotor, coil) or possibly even oxygen sensor. The oxygen sensor will clear up if you accelerate heavily then when under normal load it will start chugging again. These are a couple of areas to check without getting into serious diagnostics.

see here  for the Neon 2001 - 2008 

http://www.torbaycarstereo.co.uk/chrysler_p05091610ab.html

or if not try here

http://www.radio-code.co.uk/code-entry-help-Chrysler.htm

I have the specs and diagrams. If you want me to send them to you, give me your email address. [email protected]

check the fuel line to see if there's a flow in the line, it could be tht you need a fuel pump or your not geting a fuel flow

This could be a multitude of things but my first suggestion would be to change the spark plugs. They are cheap and can be bought at any auto parts store.

you need to get the code if you go to a auto parts store they can read it and tell you what part you need