2006 Toyota Corolla PO339, PO606, PO607 Fault - Loss of Power and Transmission Noise

I need urgent help with my 2006 Toyota Corolla (45,000 miles) that has been showing OBD-II fault codes PO339, PO606, and PO607. The car experiences intermittent loss of power—when I press the accelerator, it doesn't respond and stays at idle. When shifting from Park to Drive, the transmission makes a loud, harsh noise. To get the engine to respond, I have to turn off the ignition and restart the vehicle. This issue started in October 2010. In November, the ECM was replaced at a Toyota dealership under an official ECM recall program. Despite this, the symptoms persist. The dealer claims the new ECM is functioning properly. To date, I've visited four Toyota dealerships and three independent mechanics—none have been able to diagnose or resolve the issue. I'm seeking expert advice on what these codes mean and how they might be linked to my vehicle's performance problems.