DPF & emissions repair

What this work involves

Every modern diesel on Houston roads carries a diesel particulate filter — a honeycomb ceramic trap in the exhaust that captures soot and burns it off during regeneration cycles. Around town it works quietly. But the stop-and-go drayage runs out of the port, the idling at weigh stations on I-10, and the short hops between Baytown plants and Houston yards are exactly the duty cycle that never lets a filter complete a regen. Soot accumulates, ash packs down, and one morning the dash lights up and the truck derates to 5 mph.

The repair conversation almost always starts with a question of what kind of problem it is. A filter that is loaded with soot can often be recovered with a forced regeneration or an off-truck cleaning. Bake-and-airflow cleaning is often a same-day or next-day shop process — confirm turnaround when you call. A filter with a cracked or melted substrate cannot be cleaned back to health; that is a replacement conversation, and it costs an order of magnitude more. The diagnostic hour that tells you which situation you are in is the cheapest part of this whole process.

The rest of the aftertreatment system fails too, and it fails loudly: differential pressure sensors that lie about soot load, EGR valves sticking open on heat-soaked engines, SCR dosing problems that throw NOx codes, and DEF quality issues that cascade into derates. In the trade, aftertreatment diagnosis uses scan tools that command forced regens and read live sensor data — the difference between fixing the fault and replacing parts until it goes away. A specialty on this site only records what the shop's own pages say they do; ask whether they carry that tool.

One honest note from the data we collect: no Houston shop in our listings publishes aftertreatment prices on its site, so this page quotes none either. Call, describe the symptom and the fault code, and ask two questions — what does the cleaning include, and is there a before-and-after flow test.

Questions to ask before you agree to the work

• QWhat fault codes are stored, and does the price include the diagnostic hour to read live sensor data — or just a parts guess?
• QDoes the cleaning price include a before-and-after flow test, with numbers I can see?
• QIf the filter turns out to be cracked once it is off the truck, what happens to the quote?
• QAre you diagnosing why it clogged — regen problems, a bad sensor, duty cycle — or only cleaning the symptom?
• QIf you replace the filter, is the unit new or remanufactured, and what is the warranty on it?