SCR Technology

In order to reduce nitrogen oxide emissions the SCR technology was established - in addition to engine procedures such as exhaust gas recirculation (EGR). Nitrogen oxide is being reduced by ammonia to innoxious N2 with the aid of ammonia. (more under SCR passenger cars)

With XNOxTM SCR, Tenneco has a SCR solution for commercial vehicles ready for the OEM and retrofit market.

The XNOxTM SCR system offers all the key components such as injector, tank, pump, filters, pipes and controller. The patented injector is actively cooled by means of a continuous urea flow.

Contrary to passively cooled injectors, this provides greater flexibility regarding the choice of location.


For a quick and competitive application, especially for retrofitting SCR systems, an auto-adaptive software is available. Using this, the XNOx-specific control unit is individually programmed for each application. Thus, optimum NOx reductions are achieved even in dynamic mode.


In 2009, the first OEM commercial vehicles with XNOxTM SCR were going into production.

SCR Technology

XNOxTM SCR Demo Vehicle