Warm Up Three Way Catalytic Converter (WU-TWC) and Under-floor Three Way Catalytic Converter (Under-floor TWC)

WARNING: This page is about a different car, the 2013 Honda Fit, 2012 Honda Fit, 2011 Honda Fit, 2010 Honda Fit, and 2009 Honda Fit. However, it is still accessible from the selected car via links, so may be relevant.

The WU-TWC and the TWC convert hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) in the exhaust gas to carbon dioxide (CO₂ ), nitrogen (N₂ ), and water vapor.

WU-TWC (ATTACHED TO THE CYLINDER HEAD)

Fig 1: Identifying Warm Up Three Way Catalytic Converter

Courtesy of AMERICAN HONDA MOTOR CO., INC.

TWC (UNDER THE FLOOR)

Fig 2: Identifying TWC (Under Floor)

Courtesy of AMERICAN HONDA MOTOR CO., INC.