No. The knock sensor's job is to detect detonation, or uncontrolled ignition of fuel in the cylinders, and adjust ignition timing accordingly. With a faulty knock sensor, detonation can cause scored on the piston and cylinder walls, damaging your engine.
The good news is it's a fairly cheap part, and easy to replace. It is held in by a single bolt, and is located on top of the driver's side of the engine, just aft of the intake manifold.
The 2001 Subaru Forester has all wheel drive.
The 2005 Subaru Forester has all wheel drive.
The 2014 Subaru Forester has all wheel drive.
The 2010 Subaru Forester has all wheel drive.
The 2008 Subaru Forester has all wheel drive.
The 2003 Subaru Forester has all wheel drive.
The 2012 Subaru Forester has all wheel drive.
The 2011 Subaru Forester has all wheel drive.
The 2002 Subaru Forester has all wheel drive.
The 2009 Subaru Forester has all wheel drive.
The 2006 Subaru Forester has all wheel drive.
The 2013 Subaru Forester has all wheel drive.