Yes! Disconnecting this hose affects signals of MAF (Mass Ait Flow) sensor. If you disconnect this pipe MAF it get poor signal of air flow. Maruti DDiS also gives little bit slow throttle response if you test engine after opening of Air Filter cover. From starting point to ending point of intake air, there should not any leakage of intake air. This can be tested on Bajaj Scooter also. Remove the hose pipe & check throttle response.