Urea (SCR) Delete for
Off-Highway Trucks
The direct answer: A urea (SCR) delete is ECM tuning that disables the SCR system (selective catalytic reduction) and its diesel exhaust fluid injection (DEF, also called AdBlue), for off-highway or competition use only.
The SCR system injects urea into the exhaust to neutralize nitrogen oxides. It adds a tank, sensors, a dosing pump and a catalyst: all components prone to freezing, crystallization and failing NOx sensors, leading to engine codes and derate modes.
On 2010 and newer engines used off-highway, its removal, generally combined with EGR and DPF deletes, radically simplifies operation. Diesel Spec offers this service on Cummins, Detroit Diesel and Paccar engines.
Urea System Delete
by Engine Brand
ISB, ISC, ISL and ISX 2010 and newer, as well as the B, L, X GHG17 series: EGR-DPF-urea combinations and complete configuration with VGT.
DD13, DD15 and DD16, including the GHG14 and GHG17 generations: EGR-DPF-urea combinations and complete configuration.
PX-7 and PX-9 2010-2015, MX10 and MX13 (GHG14 and GHG17): EGR-DPF-urea combinations.
On-highway CAT engines (produced until 2010) do not use a urea SCR system: the relevant off-highway services are DPF, CGI and VVA deletes.
For the MBE900 and MBE4000, the off-highway services offered are EGR and EGR-DPF combinations.
MaxxForce engines do not use SCR: International went with a 100% EGR strategy. The relevant service is the EGR-DPF delete.
MaxxForce Off-Highway Services
An expert validates the right combination for your engine and your use.
Why Off-Highway Operators
Remove the Urea System
In intensive off-highway use, every component removed is one less source of breakdown.
A urea system delete is almost always done as an EGR-DPF-urea combination. See the EGR Delete and DPF Delete pages.
The weak points of the SCR/DEF system
- DEF fluid prone to freezing: a major constraint in the Canadian winter
- Urea crystallization in the dosing injector and lines
- Costly, failure-prone NOx sensors and recurring engine codes
- Derate mode imposed as soon as the system detects a fault or an empty tank
- Recurring DEF purchase cost over the truck’s entire life
The benefits after the delete
- No more SCR-related forced stops and derate modes
- No DEF purchases, no crystallization, no NOx sensors to replace
- Simplified operation for competition and off-highway applications
- Considerably simplified operation in intensive use
Urea (SCR) Delete
by Brand
Cummins
Models and delete services for Cummins engines.
See Cummins
Detroit Diesel
Models and delete services for Detroit Diesel engines.
See Detroit
Mercedes
Models and delete services for Mercedes engines.
See Mercedes
Paccar
Models and delete services for Paccar engines.
See Paccar
MaxxForce (International)
Models and delete services for MaxxForce engines.
See MaxxForceFrequently Asked Questions
What is the urea SCR system on a truck?
Is a urea system delete legal on the road?
Which engines are eligible for a urea system delete?
Why don’t MaxxForce engines have a urea system?
How much does this service cost at Diesel Spec?
Can a urea system delete be done remotely?
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