while my mechanic does tend to be on the conservative side of things as far as spending money on vehicles, it is i who ordered the oil pressure sender after self-diagnosing the problem. i simply presented it to him and asked him if he would replace it.

i had no idea that there were two different senders but i guess it makes sense now that i figure that the "idiot" light is for the amount of oil and the gauge is for the pressure of the oil.