Ok, this may be a dumb question, but I need the help. Can anyone tell me where the stock oil pressure sensor is on my Ecotec? I'm trying to put in an oil pressure gauge,  and I can't seem to find this. (Kinda sounds like a NEWB question...oh well) Thanks.
Rob
 
 
Then how can the oil light come on if the computer doesn't know if the pressure is low?
 
 
Ok, I found what I needed, and for anyone trying to put an electric oil pressure sensor on their Ecotec, this is where you need to get into....you'll need a t-fitting to get your aftermarket sensor, AND the switch sensor (as Shifted said) into the same hole...here's some pics....
Here's a look at where the hole is from far away, so you can get an idea of it.....
 
Here it is up close....
 
