2000 dodge neon idles fine but when in gear it chokes. Changed plugs and air filter.

Clean Throttle Body and MAF (mass air flow sensor). Classic symptoms of bad idle. The throttle body isn't shutting properly and letting air in. At highway speed it is fine because the throttle is purposely open.

https://www.google.com/search?q=2000+Dodge+Neon+clean+throttle+body

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Dodge Neon Questions - 04 neon will not go into high gear ...

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CarGurusNov 3, 2012 - 04 neon will not go into high gear - 04 neon won't go into high gear. changed transmission fluid. (it tried to change after fluid was changed) gas cap ... ... Car: 2003 Dodge Neon SXT, automatic transmission. As of today, I have ...

Dodge Neon Questions - 2005 Dodge neon does not shift ...

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CarGurusApr 6, 2014 - Your cars computer gathers info on speed in order to shift gears properly.... then you won't have a speedo and the ECM will not tell the TCM to shift gears in the trans. .... Car: 2003 Dodge Neon SXT, automatic transmission.

Neon wont shift out of first gear auto. - DodgeTalk : Dodge Car ...

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Without trouble codes you are fishing in the dark. If the engine has a cylinder that is dead at idle from a fuel injector or ignition problem, it should have a code for a miss on that cylinder. A mechanical problem like a burned valve could cause the problem without setting a code. Have you checked compression on all 4 cylinders ? ?

make sure fluid is full

This sounds like the symptoms of a choke being left on, but of course you have a fuel injected car. Could it be a computer problem, too much fuel getting to the engine?

Remove the Spark PLUGS, check the Condition, and AIR gap. If things are suspect, crank the engine to expel the debris,
out of the plug ports, and install new plugs.
I use and recommend BOSCH plugs, for your Model type, they do not have to be Air Gapped, and are virtually maintenance free for life.
Regards, DT

check vacuum lines

you might need a new idle air control module, dont adjust your idle

how many miles are on the car? try changing the spark plug wires if you have more than 60k on them

When was the last time the car was tuned up?