Yung advie ko pinalagyan ko ng nipple na 1/2" with cover dun after sa engine. nililinis ko na lang with tide and dun ko pinadadaan yung water every month ko ginagawa and yun sabay tapak sa gas pedal to spit out black carbon water about several times until malinis na yung tubig na lumalabas sa muffler. My advie is late model without any catalytic converter like more recent models.