Doser Injectors / Metering Units
The doser injector or metering unit in your truck is a crucial part of the emissions system; issues with the injector will cause fault codes and warning lights, and eventually, you might even be derated. We stock a variety of diesel exhaust fluid injectors so that you can get back on the road without worry.
The DEF injector is where the diesel exhaust fluid (DEF/urea) is sprayed into the emissions system. This happens downstream of the DPF, typically in a decomposition reactor or mixing module. After the DEF is injected into the exhaust flow, it reacts with the SCR (selective catalyst regeneration) in order to reduce greenhouse gases.
If you're noticing white smoke, a sudden drop in DEF consumption, or a 'Check Emissions' light that won't go away, a clogged or leaking injector is often the culprit. Since these units handle urea—which can crystallize and block the spray nozzle over time—replacing a failing doser is a standard part of keeping your SCR system healthy.
We carry genuine OEM injectors for Cummins (like the 5506855) and Detroit Diesel (A0001407439) to make sure you're getting the exact spray pattern your engine's computer expects.
Because we keep these in stock at our Canadian warehouses, you won't have to wait weeks for a cross-border shipment while your truck sits in a derate state.
