Recently my 2006 Crossfire Convertible has started having an engine idling problem. The car starts fine, and everything is alright at startup. Once I start driving, the engine does not go back to idle correctly. Even when shifting, the engine will continue at about 1500 RPM while shifting. When I stop the car, it idles between about 1200 and 1600 RPM, for a while, then slowly drops down to its normal 600 to 800 RPM idle. The idle is high enough that in some gears I don't even need my foot on the accelerator for the car to continue going. Eventually, though, the car will drop the RPM to normal. The car drives fine except for this problem. Is this a known problem? Any suggestions?

 

How many miles and have you scanned for codes? Possibly your MAF sensor.

 

Car has 102,000 on it. Have not scanned for any codes.

 

You can clean the MAF sensor and throttle body:
Here's a video:

 

Did the MAF cleaning and the Throttle Body cleaning, but it did not solve the problem. Any other suggestions? Is it computer related?

 

I would scan it for codes. Autozone, Pep Boys, etc will scan it for you if you don't have a scanner. Put it in as a Mercedes-Benz 2003 SLK 320.
If it's electrical it will show what it is.