Yes. Modern Freightliner heavy trucks use catalytic converters as part of their exhaust aftertreatment system, typically a Diesel Oxidation Catalyst (DOC) along with a Diesel Particulate Filter (DPF) and a Selective Catalytic Reduction (SCR) system to control NOx.
Freightliner, the brand of Daimler Truck North America, sells models like Cascadia and Columbia that rely on aftertreatment packages to meet EPA emissions standards. The specifics depend on model year and engine (for instance, Detroit Diesel DD-series engines) and region, but catalytic converters are standard in the diesel exhaust system of newer Freightliners.
How Freightliner’s exhaust aftertreatment works
In diesel trucks, the term "catalytic converter" usually refers to the DOC — a stainless steel housing containing a catalyst that oxidizes hydrocarbons and carbon monoxide and helps reduce NOx. The rest of the system adds particulate filtration and NOx reduction with DEF for compliant operation.
Below are the core elements of Freightliner’s aftertreatment system commonly found on current models:
- Diesel Oxidation Catalyst (DOC) – the primary catalytic converter in diesel exhaust that reduces CO and hydrocarbons and begins NOx reduction.
- Diesel Particulate Filter (DPF) – traps soot; requires periodic regeneration (passive or active).
- Selective Catalytic Reduction (SCR) catalyst – uses Diesel Exhaust Fluid (DEF) to convert NOx into harmless nitrogen and water; part of a larger aftertreatment module.
- DEF dosing and sensors – injects DEF upstream of the SCR catalyst and monitors system health.
These components work together to meet EPA emissions standards and reduce pollutants, with the exact configuration varying by model year and engine family.
Model-year and regional variation
Freightliner’s Detroit Diesel engines and aftertreatment packages have evolved with EPA and regional standards. The core concept remains: aftertreatment includes catalysts (DOC and SCR) plus a DPF. In Europe, packaging may differ, but catalytic processes remain central to emissions control.
Before listing the variations, note:
- EPA Tier 4 Final and Euro VI-era Freightliners typically include DOC, DPF, and SCR.
- Earlier EPA standards (pre-2010 in the US) varied by engine family; some configurations used DOCs without the full SCR/DPF combo.
The key takeaway is that modern Freightliners rely on catalytic technology as part of a comprehensive exhaust aftertreatment system.
Summary
In short, yes: Freightliner trucks built for modern emissions standards incorporate catalytic converters as part of a broader exhaust aftertreatment system. Typical configurations include a Diesel Oxidation Catalyst (DOC), a Diesel Particulate Filter (DPF), and a Selective Catalytic Reduction (SCR) system with Diesel Exhaust Fluid, all working together to reduce hydrocarbons, soot, and NOx. Exact parts and the arrangement depend on model year, engine family, and region, but catalytic technology is standard on contemporary Freightliners.
How much is a diesel truck catalytic converter worth?
→ GET QUOTE
However, many diesel converters tend to be lower in value due to the reduced amounts of precious metals like platinum, palladium, and rhodium inside. On average, Diesel Cats range in price from $15 to $477, depending on the type, condition, and content.
What happens if you remove a catalytic converter on a diesel?
Poor Emissions
It's no surprise that removing the catalytic converter (the part of your exhaust system that transmits harmful gasses into less harmful ones) will result in poor vehicle emissions. Your car will continuously be emitting harmful toxins into the environment.
Do diesel semis have catalytic converters?
Whether you have been driving big rigs for many years, or you're just beginning your journey driving semi trucks, you may have wondered, “Do semi trucks have catalytic converters?” In short— yes, they do!
Does 6.7 Cummins have a catalytic converter?
The Cummins Converter,Catalytic 5292756RX is used primarily on Tier 4 Interim 6.7 liter ISB/QSB engines.