My 96 millenia has a real rough idle and i have changed the plugs about two weeks ago and the made it not as rough but now it is rough and the plug wires are about a year old. Car runs ok when driving but when sitting still it has a rough idle. Car never dies and runs decent otherwise any help would be appreciated. Check engine light is on and it says knock sensor and 02 sensor in bank 1 but its been like that since before the rough idle started.