Wet Black Oily EGR Pipe (NOT dry soot carbon)

I have a 2010 with 200,000 miles that is "new" to me. Bought from original owner. I drove it about 1000 miles after purchase with no problems and just watched the oil level because I knew that consumption was an issue with these. It used a little oil (like 1/2 qt in 1000 miles) but otherwise ran great. I then had a CEL and had the P401 Code. Did my research here and pulled EGR cooler, valve, pipe, intake, and throttle body. I cleaned them all very thoroughly per people's instructions here on priuschat. At that time they were clogged with black powdery soot/carbon. When I put everything back it was totally clean. At that time I also installed a new PCV valve, new OEM Denso plugs, and had run BG EPR prior to previous oil change, added BG MOA to current oil (Mobile1 0W-20 high mileage and filter), and ran BG 44K through fuel tank. I also installed an Oil Catch Can after the PCV valve. I noticed after my cleaning, the prius started consuming more oil, like 1 quart in 500 miles. I pulled the EGR pipe again to see how it was after the cleaning, etc. and it was coated in sticky, black stuff. I have paid attention and the coolant level has stayed constant and the car runs great and is still getting 46mpg in city, and mountain driving. Don't really understand why there would be wet black coating inside EGR pipe. Any thoughts, help?1?1?