Flown

Hi, i have 2.0tfsi audu a4 b7 2006. And with that the ****y oil pump comes with it. I replaced the oil pump to a 1.8t and i am still havibg the oil pressure light come on. The engine sounds like normalt but the oil pressure is not good enough. The oil pressure light comes on under 2000rpm and over it goes away. Now do i need to change the sensor? If so i have a 2 pol sensor, and all the 2 pol sensors are on bars like 1,6 and upwards. Does anybody have the answer?