Try disconnecting the battery terminals again and touch both of the disconnected battery terminals together and hold for a minute. This will deplete any keep alive memory when the battery is disconnected. Reconnect the battery terminals and recheck.
If the issue is still there you'll need to have the vehicle's computer scanned for diagnostic code(s) to give a starting point for diagnosis.
If the engine is running poorly, the engine is not creating enough vacuum for the brake booster to assist in braking.
It sounds like there is an issue with the electronic throttle body but that is a guess from your description.
You could removed the intake tube to the throttle body and see if the throttle body plate is moving with some one inside starting the engine and pressing the accelerator (in park or neutral). At idle it should be mostly closed. Someone else pressing the gas pedal the throttle plate should open more.
Thanks for the question.
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Tuesday, January 20th, 2015 AT 9:01 PM