I changed oil, and now i got Engine check up warning.

leepeen

I've changed my crap QS engine oil to Pennzoil Platinum at the local autoshop near my house, and i got unreasonable engine check up warning.
I bought 5 Liters of Pennzoil platinum SAE 5W-30 full synthetic engine oil and new oil filter. i don't understand why my car's computer is saying that the car needs to get the engine service soon.
The only one thing i feel suspicious about is drain process... I was standing aside of machanic who was working on my car, and he didn't drained old oil completely, and he said it's tachically okay. Last oil was Qacker State horsepower SAE 5W-30 full synthetic oil, which was exactly same thickness and same kind. The level of oil was perfectly fine too, i've double checked dipstick at home and there wasn't any lack or overdose of oil for sure. Also, i couldn't find any sludge like before. Can anybody tell me what's wrong with my engine? plz?