While driving I heard a pop, there was a knocking noise and it lost power?

Okay, I was driving and all of a sudden, I heard a pop and some kind of like a knocking noise and it lost power, but no smoke. all the fluids are good, it's been serviced. got there and try to start the next day and it sounds more like an exhaust leak under the hood than anything and it's like leaking out some fluid stuff between if I were the old cap is in the other little part of the motor in between that little top fit is that what would be causing my truck to make a weird noise and lose power.