Engine light and tailpipe smoking

If it is a light or white smoke, you have a cooling system leak in the engine (blown head gasket or cracked head).

Heavy exhaust smoke yes. Would have any ideas on cost to repair?

Probably an expensive fix. Unfortunately there is no way to know the extent until the engine is taken apart and inspected. You should NOT run the engine as it can further damage things. If the coolant leak is bad, coolant can get into the oil (check the oil to see if it is milky). The spark plugs can be removed to determine which cylinder(s) are getting receiving the coolant. Then the cylinder heads will be removed and checked.