Help, my 2010 Cube engine won't accelerate above idle speed when in gear. When I start the engine it starts and idles fine. However; when I push the accelerator down nothing happens most of the time. It just stays at idle. Once in awhile, the engine will accelerate, so I know the trans is working. I have replaced the mass air flow sensor and checked the air filter. I'm told there's not a fuel filter outside of the gas tank, but it looks like one in a line behind the throttle body and to it's left when standing in front of the car. I'm at a loss as to what to do for it. Any constructive ideas or history with this type of a problem on a Cube?

Run computer for codes, something should be marked in there.