Emission System Core: Cummins B6.7 / L9 DOC (2018–2022)
What is it?
The DOC (Diesel Oxidation Catalyst) for Cummins B6.7 and L9 engines (2018–2022) is an essential emission control component. It chemically converts harmful pollutants like carbon monoxide and hydrocarbons in the exhaust stream into less harmful gases before they enter further aftertreatment stages.
Why choose the OEM DOC?
This DOC is engineered specifically for the B6.7 / L9 platform within the 2018–2022 model years. Using the correct DOC ensures proper emission control, avoids increased backpressure, and reduces the risk of system faults or failed emissions tests. It’s built to match factory performance and compliance requirements.
Key Benefits
✅ Tailored for Cummins B6.7 and L9 engines (2018–2022)
✅ Reduces carbon monoxide and unburned hydrocarbons effectively
✅ Supports downstream SCR and DPF systems by preconditioning exhaust
✅ Durable design tolerates high exhaust heat and corrosive conditions
✅ Drop-in replacement with correct fitment and mounting
Applications
The DOC fits medium-duty trucks, buses, generators, and other equipment powered by Cummins B6.7 or L9 engines in the 2018–2022 period. It aids emission compliance, system longevity, and performance consistency in emissions systems that include SCR, DPF, or other post-combustion components.
Installation Notes
Ensure the system is powered down and fully cooled before working. Remove the existing exhaust component, inspect flanges and gaskets, and clean mating surfaces. Install the new DOC, torque fasteners to Cummins spec, and verify sealing integrity. After installation, monitor exhaust flow and system diagnostics to confirm proper function.
Final Thoughts
When your Cummins B6.7 or L9 engine needs reliable emission treatment, a properly matched DOC ensures your system starts cleanly and supports downstream components. With correct design, durability, and OEM compatibility, this unit helps keep your engine’s aftertreatment system effective and compliant.