[suprra_girl]

once you have found the faulty knock sensor/circuit repair it as soon as you can

if you leave the wire joined it will trick the ecu and if it does start knocking the ecu won't realise and retard your timing to save your engine

basically in an easy statement: no, it's unsafe and you'll more than likely blow it up

and the check engine light will only come on if a knock sensor or circuit is faulty not if the engine is actually knocking