Picked up my car with a new radiator and thermo today, the mechanic said I had a bad leak coming from the oil sensor. So I bought a new one for 4 bucks at autozone today, and i'll be putting it in tomorrow. Any advice, anything I have to watch out for?

And im assuming I have to do this after I drain the oil, right? I was gonna change it tomorrow anyways. Its 1000 miles overdue

 

oil sensor? 4 dollars? what sensor are you talking about? i had to replace the oil pressure sending unit for the gauge in the car and that ran about 20 bucks. what year car do u have and whats the sensor for?