Engine shakes and rough idle
 

Hi there. I have a 99 Camry V6 AT. The problem is when I drive it for about 20min or longer on the freeway and come to a stop the engine shakes and it idles rough, but never dies. The engine shakes and the idle bounces from 400rpm to 1100rpm. But when I step on the gas it runs fine, no power loss.
And when I turn off the car and let it sit for about 15min it will be fine again. This doesn't happen every day just once or twice a week.

No CEL. So theres nothing to scan for. Any ideal?
Thanks

RE: Engine shakes and rough idle
 

timming maybe?

RE: Engine shakes and rough idle
 

No, its not the timing belt. It happen before and after I got the timing belt change by the dealer. Tried taking it to the dealer, but it never happens when they have the car, they check a few time already and couldn't find anything wrong.