apenutts

My 1997 Lexus LX450 starting smoking from the exhaust manifold. I replaced the valve cover gasket but it's still smoking. It's coming from the rear exhaust manifold. I took off the exhaust shield and noticed some oil leaks by the engine block. Will an exhaust manifold gasket repair the issue or do I have an internal engine issue? My LX450 has 198k miles and the oil light comes on every 3,000 miles.