24/7 mobile dispatchBakersfield, CA · I-5 · CA-99 · SR-58 (661) 546-9200
Diagnose the system, not only the warning

DPF, DEF & Aftertreatment Diagnostics

Testing for regen, DPF, DEF, SCR, NOx sensor, temperature sensor, dosing, and derate problems.

Aftertreatment faults are affected by engine-out emissions, exhaust leaks, temperature, pressure, sensors, dosing, DEF quality, wiring, drive cycle, and component condition. A forced regeneration alone will not correct a fault that prevents the system from operating properly.

Scope of service

What we inspect and repair

Fault-code, history, freeze-frame, and live-data review

DPF differential-pressure and exhaust-temperature evaluation

DEF level, quality indication, heater, pump, line, and dosing checks

NOx, temperature, pressure, and related sensor circuit testing

SCR efficiency and dosing-system troubleshooting

Exhaust leak and connection inspection

Regen eligibility, inhibit, and failure-cause diagnosis

Engine-performance causes that create soot or block regeneration

When to call

Common symptoms and repair needs

  • DPF, DEF, check-engine, or stop-engine warning
  • Regen requested, inhibited, failed, or too frequent
  • Progressive power derate or speed limitation
  • DEF consumption changes or crystallization is visible
  • Repeated NOx, temperature, pressure, or efficiency codes
Equipment coverage

Common vehicle and trailer types

EPA-emissions-equipped highway tractorsMedium-duty commercial diesel trucksFleet and vocational diesel equipmentCommon heavy-duty aftertreatment architectures

Service capability varies by year, make, model, component, fault, parts, and work conditions. Provide exact equipment details when calling.

Questions answered

DPF, DEF & Aftertreatment FAQs

Can you perform a parked regeneration?+

A regeneration may be appropriate only after the system meets the required conditions and faults that block or endanger the process are addressed. Diagnosis comes first.

Do you delete or bypass emissions systems?+

No. We support lawful diagnosis and repair of the factory-designed emissions system and do not advertise defeat or tampering services.