Float needle sticks in carb and allows excess fuel to seep past rings into oil.
No spark.
Bad valves !
CAUSE WHEN YOU drive you burn fuel
A lean burn system is a fuel burning system that uses an excess of air in an internal combustion engine. They provide a high air to fuel ratio and are used in some vehicles.
too much fuel, excessive oil consumption
If your car is misfiring then you will need to get a tune-up. If you don't you will continue to burn excess fuel.
Excess fuel causes black smoke.
Yes it would. O2 sensors work with the car's ECM to tell the car how to burn the fuel and how the fuel is burning. This is a strong possibility.
Under inflated tires, dirty air filter, bad O2 sensor, out of date tune up/fuel system tune up, excess weight in car, hard driving conditions
it may have somthing in gas line or your fuel pump may be going out
Have the cold start injector checked