Accordztech is right. You need to prioritize your issue's.
You Check engine light is there for a reason. All the rest of the issue's don't mean anything until you get the CEL worked out.
A 4 banger really doesn't have that much juice to begin with so you start loading it with the A/C compressor, the Alt for the lights, and esp being in gear all while at idle, your going to notice a difference! Esp if it's not running right from the get go.