This bulletin applies to 2011 Dodge Ram Cab Chassis models equipped with a 6.7L diesel engine. A MIL on and DTC P1C56 (NOx sensor intermittent, Bank 1 Sensor 2) may be found.
This involves verifying excessive diesel exhaust fluid (DEF) deposits in the decomposition tube collected. If present, it is necessary to replace the catalytic converter shield with a “clam shell” shield that features a metal exterior.
The condition may be caused by insufficient heat retention in the exhaust at or near the DEF doser.
When diagnosing and repairing 2011 trucks with a blanket type catalytic converter shield, replace the shield with P/N 68086554AB after completing diagnostics and repairing any concerns.