rough idle hesitating

Hello, I'm a long time xB fan and owner, though I don't post here often. I really really need some help with an issue I have with my 2004 Scion xB RS 1.0 Automatic Transmission. Intermittently my car will not accelerate at all, meaning no matter where you put the throttle pedal you get nothing...

Hey, I've had this problem for A year now. I'm just frustrated with my 2011 XB, it has 75,000 miles & still idles rough around 600 rpm @ stop light, no check engine lite. I've tried everything, cleaning TB, cleaning maf, Replacing Spark Plugs, Luscas & techron Fuel system cleaner, resetting ecu...