Your Diesel Engine Has Enough Work to Do Without Fighting Its Own Exhaust.
A truck that keeps requesting regeneration. An engine losing power halfway through a haul. A check engine light that refuses to disappear.
When your EGR or DPF system starts acting up, productivity can take a serious hit.
At Miller’s Repair, we help diesel truck owners, fleet managers, and equipment operators troubleshoot exhaust gas recirculation (EGR) and diesel particulate filter (DPF) problems.
From clogged filters to malfunctioning EGR valves, we identify what's affecting your engine's performance and determine the repairs needed to get your equipment running properly.
Soot Happens. Here's How We Handle It.
Modern diesel emissions systems are designed to reduce harmful exhaust emissions, but they also depend on sensors, valves, filters, and electronic controls working together.
When one component isn't doing its job, the problems can spread throughout the system.
Our EGR & DPF Services Include:
- DPF Diagnostics – Investigate filter restrictions, soot accumulation, and related fault codes
- DPF Cleaning & Service – Evaluate filter condition and appropriate cleaning options
- Regeneration Troubleshooting – Diagnose failed, incomplete, or excessively frequent regeneration cycles
- EGR Valve Repairs – Address sticking, malfunctioning, or carbon-affected valves
- EGR Cooler Diagnostics – Investigate coolant loss, leaks, and cooler-related concerns
- Exhaust Pressure & Temperature Sensors – Troubleshoot faulty readings and sensor-related problems
- Emissions System Fault Codes – Identify issues involving exhaust aftertreatment and electronic controls
- Related Wiring & Component Repairs – Address damaged connections and other electrical faults
Service options depend on your engine, emissions system configuration, and diagnostic findings.
When Your Truck Starts Complaining, Don't Ignore It.
An emissions system problem doesn't always mean an immediate breakdown. But overlooking the warning signs can lead to reduced engine performance, operating restrictions, and costly repairs.
Common Signs of EGR or DPF Trouble:
- DPF Warning Light – May indicate soot accumulation or a regeneration issue
- Frequent Regeneration Cycles – Could signal excessive soot production or system faults
- Reduced Engine Power – May occur when the engine enters a protective derate mode
- Poor Fuel Economy – Can accompany certain emissions system problems
- Check Engine Light – May point to EGR, sensor, or aftertreatment faults
- Unexplained Coolant Loss – Can sometimes indicate an EGR cooler problem
The same symptom can have several causes. Accurate diagnostics help determine whether the issue involves the filter itself or another component affecting its operation.
A New Filter Won't Fix an Old Problem.
A restricted DPF isn't always the root cause.
Fuel system issues, excessive soot production, faulty sensors, exhaust leaks, and malfunctioning EGR components can all interfere with regeneration and aftertreatment performance.
Simply replacing a filter without investigating why it became restricted may leave the original problem unresolved.
At Miller’s Repair, we focus on the bigger picture: identifying contributing issues, recommending appropriate repairs, and helping your emissions system operate as designed.
The goal isn't just clearing a warning light. It's addressing what triggered it.
DPF Light On? Call 720-910-7456 Before Your Truck Derates.
An emissions warning can go from annoying to expensive when your truck begins losing power or requires an unplanned stop.
Tell us about your engine, any active warning lights, regeneration problems, and performance changes. We'll discuss next steps to diagnose your EGR or DPF issue.
Call 720-910-7456 to Schedule EGR & DPF Diagnostics and Repair.
Freight Doesn't Wait for a Regeneration Warning.
Diesel trucks spend their days hauling along I-76, navigating Denver traffic, and covering long stretches of I-25. Those demanding routes are no place for recurring emissions faults or unexpected engine derates.
For operators passing through northern Colorado, Miller’s Repair has a shop at 471 Co Rd 27, Brighton, CO 80603.
Our mobile service territory also extends along the I-25 corridor from Colorado Springs to Cheyenne, Wyoming. Whether you're managing a local fleet or dealing with trouble on the road, call to confirm which diagnostic and repair services are available at your location.
EGR & DPF Repair FAQs
What's the difference between an EGR and a DPF?
The EGR system recirculates a portion of exhaust gas into the engine to help reduce nitrogen oxide emissions. The DPF captures soot from the exhaust and periodically removes accumulated soot through regeneration.
Why does my truck keep requesting DPF regeneration?
Frequent regeneration can result from excessive soot production, interrupted regeneration cycles, faulty sensors, exhaust leaks, or other engine and aftertreatment issues. Diagnostics are needed to determine the cause.
Can a clogged DPF be cleaned instead of replaced?
Sometimes. Cleaning may be appropriate depending on the filter's condition, the type of contamination, and manufacturer requirements. Cracked, melted, or otherwise damaged filters may require replacement.
Do you repair EGR and DPF systems without deleting emissions equipment?
Yes. EGR and DPF service should focus on diagnosing faults, repairing or replacing components, and maintaining the emissions system's intended operation. Miller’s Repair does not need to remove or disable emissions controls to address these problems.
