Fm radio in my car stopped working

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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you will have to have the key programmed to the different immobilizer and the immobilizer programmed to the ECM

Sounds like the transmission cooler tank with in the radiator has gone bad, the transmission lines can go on either way, does not matter, replace radiator and have cooling system flush and have a transmission flush also done.

I would suspect something like a faulty mass airflow sensor, but why not take the car to an autoparts store and have them use a scan tool to retrieve any fault code(s) that are stored in the computer. Most parts stores offer this service for free. Getting the codes should end speculation and narrow down the cause of the problem. Sure hope this helped and best wishes.

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

I dont think it would be the fuel pump, or else no fuel would to delivered to the engine.
i would try cleaning the throttle body first, as dirty throttle body's can cause rough idling and stalling while stopped or slow speeds.

Check mounting surfaces at antenna. Corrosion or looseness and the antenna loses its ground to the body.

open the hood,,,look inside to the right,,and down,,,you will see a plug or dip stick tube,,,this is where you put the tranny fluid.

the most common oil leak is the front cranshaft seal, as for the 3rd brake light replace the bulb(s)

Check your altenator.