2004 grand marquis idles up and down on it's own when i come to a stop
Probably responding to unmetered air, check for vacuum leaks, PCV valve/elbow is a good place to start.
thanks i'm gonna take a look at that
Throttle position sensor and or bad gas and fuel filter just my opinion
Throttle position sensor TPS and bad gas prob fuel filter especially if u dont keep alot gas In it gas sucks bad these days
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