When parked car idles weird (at stop signs too). When running its fine.?

Hello, You may have an issue with your EGR valve , which would send too much air into the engine at idle, or your EVAP purge valve is stuck open, and sucking in air from your fuel tank. In either case, a lean running condition is attributed to too much air for the amount of fuel being send into the engine. You'll be best off having a professional scan test performed, otherwise you really will throw lots of parts at this vehicle until the right part is found.