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Diesel exhaust system repair at Route 66 Auto Repair in Upland covers leaking joints, broken hangers, cracked pipes, failed sensors and the warnings that come from a diesel's aftertreatment system. Our ASE-certified technicians find the cause and repair the system to factory form. We never delete or bypass particulate filters, EGR or DEF equipment, and your written estimate comes before any work.
What is in a diesel exhaust system?
Behind the turbo, a modern diesel pipes exhaust through an oxidation catalyst, a particulate filter that traps soot, and on many trucks a system that injects diesel exhaust fluid (DEF) to cut emissions. Temperature, pressure and emissions sensors report to the engine computer. A leak upstream of a sensor, a cracked sensor line or a failing sensor can set warnings that look like a bigger problem than they are.
The pipes, clamps and hangers still take a beating from heat, vibration and the potholes on the way to the job site. A broken hanger can let the system sag and crack a joint.
What are the signs of a diesel exhaust problem?
- A ticking or puffing sound that is loudest on a cold start
- Soot tracks around a joint or flange
- A rattle or clunk from under the truck over bumps
- Particulate filter, DEF or exhaust sensor warnings
- Exhaust smell in the cab, which is a safety issue
Our diesel exhaust repair process
Step 1: Inspect on the lift
We look for soot tracks, cracks, broken hangers and damaged sensor wiring.
Step 2: Read the data
Sensor readings and codes show whether a warning comes from a leak, a sensor or a restriction.
Step 3: Estimate in factory form
The written estimate repairs or replaces parts to the original configuration.
Step 4: Repair
Gaskets, clamps, hangers, pipes or sensors are replaced and torqued to spec.
Step 5: Verify
We recheck for leaks and codes and road test the truck.
What's included in diesel exhaust repair
Included on the work order
- 01Underbody exhaust inspection
- 02Code and sensor data review
- 03Leak check at joints and flanges
- 04Hanger and clamp inspection
- 05Repair to factory configuration
- 06Post-repair code check and road test
Is diesel exhaust work need-now or need-later?
Need now: call
- Exhaust smell inside the cab
- A leak near wiring, fuel lines or the cab floor
- An aftertreatment warning with reduced power
Need later: book
- A small soot track on a joint far from the cab
- A worn hanger insulator that still holds
Will we remove a particulate filter or EGR?
No. Removing or disabling emissions equipment on a road vehicle is illegal, and we do not do it or install software that hides it. We also do not perform state emissions inspections. We diagnose why the system is struggling, whether it is a sensor, a leak upstream, an injector problem or driving that never lets the filter clean itself, and quote the repair that keeps the truck legal.
How pricing and timing work
Hangers and clamps are usually quick. Sensors vary by location, and seized fasteners add time. Aftertreatment parts can be expensive and may need to be ordered, so we confirm the cause before quoting them. Phone quotes are ranges until we inspect. AAA members get 10% off parts and labor, up to $75.
Aftercare
A longer highway drive helps the particulate filter clean itself after sensor or leak repairs. Manifold leaks are covered on diesel exhaust manifold repair. For gas vehicles see exhaust repair, and our exhaust leak inspection is a good yearly check.


Frequently asked questions
Why does my particulate filter keep clogging?
Often because the truck never runs long enough at highway temperature to burn off soot, or because an injector, EGR or turbo problem is making extra soot. We look for the cause instead of only treating the filter.
Can a small exhaust leak set a warning light?
Yes. A leak ahead of a pressure or temperature sensor can skew its reading and trigger an aftertreatment code.
Do you work on DEF systems?
We diagnose DEF warnings and repair the system to factory form, with parts listed on a written estimate. We do not disable it.
