on D series motors (i am pretty sure all of them) your ol pressure sensor is just above your oil filter. you cant really see it well with the motor in the car unless you are under it with teh oil filter off. then you will def. see it. you'll see a rubber boot with one wire coming off. just pull the cap off and you'll see a large sensor. i used a 15/16" socket to get mine out. i think it's actually a 20mm.