So I've had the "check oil" message showing up on my dash of my GT every time I start the car for the past couple of weeks. At first I thought maybe I was a quart low so I checked it on the dipstick and the level was fine. The next thing I did was change the oil as well as the sensor that's in the side of the pan. But still the "check oil" message comes up. The next thing I tried was changing the oil pressure sensor and screen on the back of the motor behind the intake manifold. I used all GM parts. But still I'm getting "check oil" on the instrument cluster. The oil pressure gauge on the center stack reads normal oil pressure. I have not tried to hook up a gauge to see what it's reading but maybe I should? Any other ideas on what could possibly be causing this? The car is 2008 model with 150K miles on it. Engine is stock with the exception of having DOD turned off through the ECM.