If it's over 10% try to listen where it's leaking from.
Leaking out the exhaust = Exhaust Valve
Leaking into the intake/throttle plate = Intake Valve
Air bubbles in the top of the radiator(take off the rad cap) or into the adjacent cylinder = headgasket
Oil cap, Dipstick, Bottem end = Piston Rings
And everyone's right, my gf's car started misfiring like crazy with the flashing CEL and all that. We bought it not too long ago and it turned out the distributor rotor came loose, but this lead us to find it has an accord timing belt among other stuff.
Leaking out the exhaust = Exhaust Valve
Leaking into the intake/throttle plate = Intake Valve
Air bubbles in the top of the radiator(take off the rad cap) or into the adjacent cylinder = headgasket
Oil cap, Dipstick, Bottem end = Piston Rings
And everyone's right, my gf's car started misfiring like crazy with the flashing CEL and all that. We bought it not too long ago and it turned out the distributor rotor came loose, but this lead us to find it has an accord timing belt among other stuff.