Why does my car stall when I release the gas pedal

I own a 2005 Dodge Neon. While it's in neutral, I push in the clutch and start it. It idles, but when I take my foot off of the clutch, it stalls. When I try to restart it, it rattles and won't start. I wait about 10-15 minutes and it will start as long as I keep my foot on the gas. When I take my foot off of the gas it stalls and then the whole rattle ordeal starts again. I recently had the CAM sensor, spark plugs and the air filter replaced.