tell me what yall think i start my car in the morning i starts fine but as soon as it fires it idles down to 500 to 600 rpms and is there for about 15 mins then its fine around 800 to 900 rpms it did it when it was summerish and still here in the winter not sure if its the dpfe sensor cause it threw an egr excessive flow code about a mth ago but i cleared it and hasnt come back on. so i dont know if its the iac, or the dpfe sensor