48 hours after quitting smoking, carbon monoxide will be eliminated from the body. Lungs start to clear out mucus and other smoking debris.
Source: What happens when you quit? @ NHS Smokefree
Image by Challiyil Eswaramangalath Vipin from Chalakudy, India (cigarette.. like a cigarette in the rain) [CC-BY-SA-2.0], via Wikimedia Commons
