My Chevrolet Cobalt 2010 2.2 LT has been shaking and stalling when in idle. After reading multiple forums, I decided to try cleaning the throttle body. I took it off completely and cleaned it with throttle body cleaner. I also cleaned the air intake sensor with mass air intake sensor cleaner. After putting everything back on, the car displayed a message saying "engine power reduced" and it makes a clunking sound between 25-55mph. Any ideas on what could be the problem, one problem keeps happening after another! Thanks in advance!!