I just bought 2010 Tahoe..242 k on it I was told truck had no issues, have had it for three weeks now and check engine light came on and it was a quart low on oil.. I added quart of oil and light went off. only thing I noticed wrong other than it needing oil is the cool air/mass air flow filter is really dirty...I also smell a rotten egg smell from exhaust and ran a cleaner through it...it has been a week and check engine light is on again and it is a quart low again. No visible leaks and nothing on ground when parked...I'm a single mom and don't know much about this truck.