Chevrolet Repair: 2000 Saturn LW2 station wagon, saturn lw2, oxygen sensor

Question
I have a Saturn station wagon with a v6. the other day on my way home from work heard a loud knocking noise couldn't pin point exactly where coming from but do know it is from engine by the time i got to the house approximately 30 miles noise turned extremely loud and sounded like the muffler dropped and i was dragging it behind so i looked and muffler still intact but the car was still making a horrendous clacking noise not sure what it could be any suggestions would be very helpful or if i just need to let a tech look at it either way any help will be greatly appreciated thank you for your time and help

Answer
HI JUSTIN, WITHOUT HEARING THIS IT IS TOUGH TO SAY.I WILL MAKE SOME GUESSES. IF THIS NOISE IS A EXHAUST NOISE CK FOR A SPARK PLUG THAT MAY OF COME OUT OF THE HEAD,THIS WOULD CAUSE A LOUD  NOISE,THE OTHER POSSIBLE CAUSE IS A OXYGEN SENSOR COULD OF BLEW OUT OF THE EXHAUST. YOU HAVE TO PINPOINT WHERE THE NOISE IS FROM, MAYBE LIFT THE CAR AND GET UNDER IT. IF YOU DO NOT THINK IT IS A EXTERNAL NOISE THEN THE ONLY THING LEFT IS A INTERNAL NOISE, SUCH AS ROD BEARING NOISE,THIS IS NOT GOOD IF THIS IS THE NOISE. IF THE ENGINE RUNS SMOOTH I DONT THINK IT IS A ROD NOISE,THAT NOISE WOULD SOUND LIKE A HAMMER HITTING METAL,KNOCK,KNOCK, KNOCK FROM THE LOWEWR END OF THE MOTOR. LETS HOPE THIS IS NOT THE NOISE..GET ME MORE INFO IF YOU CAN,HOPE THIS HELPS TOM..