Can someone direct me to a thread or explain what the problem might be when I turn the car on and have the gear select in P (duh), it idles very high for about 5-10 seconds and then drops to 600 rpm and pulses up to 1000 rpm repeatedly like a heartbeat? The check engine light is on. That's about all I know for now. Have had the car for 6 days and can tell no problems yet. Thanks.