The car does not carry one. I believe the it was up to certain individuals as a security measure. A control measure to have a higher payment in gasoline. Why else would its manual state that 91 or premium should be used. Yes, it does say that regular can be used but that this would damage the engine in the process if it was to be used often. Why not install one to begin and allow the owner to decide what octane to be used?
The fuel filter on an Acura TSX is located in the trunk. Under the panels there is an access door.
Purchase a Purolator Cabin Filter. It comes with detailed instructions.
The 2008 Acura TSX runs on premium unleaded (recommended).
The 2004 Acura TSX runs on premium unleaded (required).
The 2005 Acura TSX runs on premium unleaded (required).
The 2013 Acura TSX runs on premium unleaded (recommended).
The 2010 Acura TSX runs on premium unleaded (required).
The 2009 Acura TSX runs on premium unleaded (recommended).
The 2011 Acura TSX runs on premium unleaded (recommended).
The 2006 Acura TSX runs on premium unleaded (required).
The 2007 Acura TSX runs on premium unleaded (required).
The 2012 Acura TSX runs on premium unleaded (recommended).