Code 43 is for the starter signal to the ECU... I don't think that is related to the problem at the moment.
Try placing a jumper wire between the Fp and B+ connections on the diagnostics port in the engine bay. If the motor stays running, you have a defective AFM (air flow meter, on top of the airbox).
Did somebody recently remove the airbox lid (and unplug the wiring harness)? If done incorrectly, it can damage the AFM internals and cause the problem you are describing. The car should not run with the air intake tube remove also (a sealed intake from the AFM to the throttle body is required for proper running of the motor).
-Charlie
PS. I have 2 extra known good working AFMs...