I have a 2000 Integra GS with 231k miles and my check engine light on. Car intermittingly hesitates, knocks and feels sluggish on acceleration. (The codes read po304 and po1399) I have replaced; spark plugs, wires, distributer assy, vacuum hose, catalytic converter, and 02 sensor (since August). After CEL was reset car drove fine for a couple days, today CEL came back on with the same problems as before. Has anyone had this problem and can you suggest a solution. Thanks Ed.