Mazda notes that you should not adjust the throttle adjustment screw (TAS) on fuel injected vehicles with idle speed control motors at any time. The TAS functions as a stopper when the throttle valve is fully closed. During production, the TAS is accurately set by measuring the airflow rate past a closed throttle plate. Any adjustment to this screw will affect PCM control of idle speed.
Tampering with this screw will affect the idle contact switch and/or throttle position sensor settings. Applicable models include 1995-2007 B-series, 1997-2003 Protégé, 1997-2005 Miata, 1997-2002 626, 1997-2002 Millenia, 1997-2006 MPV and 2001-2006 Tribute.