P226DParticulate Filter Deteriorated/Missing Substrate (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P226D means the bank 1 particulate filter offers so little flow resistance that its core is likely broken, burnt out or removed. CARB requires detection of a destroyed or missing substrate, or a filter replaced by a pipe. GM's diesel tables test the filtered resistance of the DPF during soot loading above 500 rpm and 10 l/s exhaust flow: 5 failures in 10 samples (2018) or 20 in 30 below 0.01 kPa per l/s (2025), Type A. GM adds that a loose or blocked pressure-sensor pipe gives the same result; PIP5664 and an ECM update dealt with false P226D on 2020 6.6L L5P trucks, as did Mack and Volvo for 2015-16 MP engines. Ford also uses P226D for petrol particulate filters (2024-25: normalised back pressure below 1.0 for 5 s); 2025 Maverick and Bronco Sport 2.0L had the wrong pressure sensor fitted.
- What you may notice
- MIL on
- Visible soot at the tailpipe if the filter core is damaged
- Often no driveability change; regeneration behaviour may be affected
- Likely causes
- LikelyFilter core cracked, melted after an overheated regeneration, or removed
- LikelyDifferential pressure line disconnected, cracked, blocked or routed wrongly
- PossibleControl software that sets the code without a hardware fault
- RareIncorrect or faulty differential pressure sensor assembly
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €50 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.