It could still be the turbo. I have seen them lock up of wear out. Typically from lack of maintenance. I had one PT awhile back that had no power. After checking it out I found the turbo had approx 1/2 play up and down. Car had 24,000 miles on it. Still had the FACTORY INSTALLED oil filter! HMMMMMM... wonder what caused the failure?
Just an example. Not implying anything.
Is the check engine light on? How bad is the power loss? Slight or massive?
Some oil is normal. A mist or some small drops ok. It it's dripping out or has puddles of oil that's not good.