WARRENVILLE, Ill. — Navistar International says it has withdrawn its lawsuit against the California Air Resources Board (CARB) that accused the agency of improperly certifying 2010 diesel engines using selective catalytic reduction (SCR).
Navistar sued because it feld CARB was applying ceritification requirements which permitted SCR-equipped diesel-powered trucks to operate “for extended periods without any control of NOx emissions.”

“The 2009 Guidance allows engines to operate for multiple and lengthy periods of time with the NOx emission control SCR Systems turned off, causing uncontrolled NOx to be discharged into the air,” Navistar charged.

Navistar said it has received an admission from CARB that the 2009 guidance documents in question are not its policy. CARB agreed to convene a public workshop no later than August to address the issues Navistar raised.

Navistar’s hope is that the outcome will eliminate the opportunity for SCR-equipped trucks to operate with uncontrolled Nox emissions for lengthy periods of time.

“We are pleased that CARB is taking this action and we look forward to participating in the workshop,” said Jack Allen, president of Navistar’s North American Truck Group. “We expect that our agreement with CARB will result in equal enforcement of the 2010 NOx requirements for all engine makers.”