ok so i just tested my kr gauge by hitting the oil pan with a mallet and the gauge didn't move one but stayed at 0.0 and then over the past couple of days i keep getting random readings like 0.2 ,0.5 and 0.7, does anyone know what could be wrong ? like i said i replaced both knock sensors and they are both plugged in. could i possibly tap the sensor itself to see if it will change ?