I have a 2004 Lancer and was wondering where the oil pressure sending unit is located. Mine has gone faulty, I have bought the part, I just need to know where it is in my engine. Thanks!

 

It's #1 in the part explosion, should be on the block above the oil filter. And before you take the old one out, check the size of the hex on the new one compared to the old one, I replaced one of these on my buddies honda and I had to use 2 different size sockets.