Coming to stop, idle drops too low, eng shakes then recovers

[M37owner]

So, when I come off the highway and come to a complete stop, sometimes the idle speed drops too low (like to 500), the engine shakes for a second then the rpm recovers (to 700 +/-).
What is the common cause of this - dirty throttle body?
Car has 40K miles.
Thanks

[lovemycarM35]

Any codes? I would start by checking the air filter and yes throttle body

[M37owner]

I did not connect a scanner to look for codes, but the Check Engine light has not come on.
Air filter is new. Maybe its time for a fuel-injector/throttle-body cleaning.

[beachbum718]

Could be has gas.could be loose spark plug wires.could be alot of things.bring it to an honest mechanic.check transmission fluid....main drive belt.make sure its tight

[King James]

I had the same issue took it to the dealer and there was a new program they told me would fix it. so they did a reprogram of the ECU and it hasnt happened since.