2001 Honda Accord Oily, smokey, gassy exhanust

Hello guys! Im starting to notice that my car is smoking when I take off from stop sign or red lights. The car has 298,000 miles on it and it runs absoultely great. I still get all service done at my local honda dealership. They did an engine compression test and everything came out well. I do have a leaking rear main seal and I wonder is this causing veh to smoke from muffuler? Can it be that, pcv, manifold or what have you. I'm not a car mechanic or anything. Please help!