I took a '96 Lexus LS300 in for an oil change. It seems they added 5 quarts, but not take old oil out.
Within a few miles I was blowing so much smoke that there are bugs left in Northern Virginia.
I returned to the place where the oil was added, and they removed all of the oil and added a fresh 5 quarts.
Within 300 yards, no more smoke. Will there be long term problems? Do need to do anything?