Was leaving to the store, got 1/2 mile down the road when I see a huge cloud of black smoke coming out my exhaust...car started to act like it was going to stall but didnt... I pulled over until the smoke cloud cleared and proceeded to drive back home and it was fine. This keeps happening every 5 miles or so... No warning lights came on on the dash so it's not throwing any codes... I changed the air filter, cleaned the MAS sensor ( i think thats what its called) and went and bought a Dorman PCV valve replacement kit and had that installed...Now today it's more of a white/ gray colored smoke out the exhaust. Had it tested for a cracked head gasket and that was negative...HELP!