Yes, that can cause an issue. The mass air flow sensor (MAF) iss before the Throttle Body. If the engine is sucking air because the intake air tube isn't connected, the MAF is being bypassed or sending incorrect information to the PCM. Thus, the computer is trying to compensate and causing the idle to increase. Check that first. If that doesn't fix the problem, make sure nothing was left disconnected and there are no vacuum leaks to the engine. It's easy to bump a hose and not even realize it's disconnected.
Let me know what you find.
Thursday, March 5th, 2015 AT 7:17 PM