The vacuum lines are not brass but the do slide over brass tubes like below
one is plugged and the other has a line that goes to a fuor port plastic connector thrre small lines one from each throttle body hooks to it and then a large one runs from it to the MAP sensor if your loosing to much vacuum it will throw a voltage alarm in the ecu. Which is the code your getting. Its either that or the electronic plug is off the map sensor. This is what throws the engien light. save yourself some money and chase them down. It could just be the plug on the map sensor or the large hose.