Honda Accord Diesel Particulate Filter DPF

The Diesel Particulate Filter (DPF) on Honda Accord diesel models like the CL7 (2.2 i-CTDi 140 HP, N22A1 engine, CN1 standard) or the VIII Tourer (2.2 i-DTEC, Euro 5) is a key component designed to capture cancer-causing fine particulate matter from diesel exhaust gases. It is located in the exhaust line after the turbocharger and includes an integrated catalytic converter. The DPF helps reduce harmful emissions by filtering soot and soot regeneration cycles that burn accumulated particles at high temperatures.

The DPF operates through two main cycles:

• Filtration Cycle: Exhaust gases pass through porous walls that trap solid carbon particles, forming a soot layer monitored by pressure differential and temperature sensors.
• Regeneration Cycle: The engine control unit initiates a combustion process around 600°C to burn off the soot. This can be passive or active and often requires driving continuously at speeds of 60-80 km/h for about 25-30 minutes.

The typical layout is Engine → Turbo → DPF (with sensors) → Exhaust.

Signs of a defective DPF on Honda Accord models such as the CL7 2.2 i-CTDi include:

• Increased fuel consumption
• Loss of engine power
• Illumination of the Check Engine or pollution warning light
• Detection of obstruction by sensors which may limit turbo performance (engine limp mode)

Note: Older Honda Accords (pre-2008) might not have a DPF but instead a catalytic converter, with common issues related to the EGR valve or turbocharger.

DPF maintenance includes:

• Manual regeneration by driving continuously at 60-80 km/h for 25-30 minutes
• Using diagnostic tools like VCDS to force regeneration
• Using specific cleaning products designed for DPF maintenance (e.g., diesel DPF cleaners in aerosol form)
• Monitoring soot and ash levels, with ash content ideally below 60 grams

Short urban trips should be avoided as they promote DPF clogging by preventing complete regeneration.

It is generally recommended to replace the DPF between 140,000 and 180,000 kilometers to avoid serious failures.

• Ensure compatibility with your specific Honda Accord model and engine (e.g., 2.2 i-CTDi / i-DTEC)
• Verify compliance with emission standards (Euro 4, Euro 5, CN1, etc.) before purchasing
• Replacement should be done by a professional to guarantee correct fitting and sensor integration

Proper fitting is essential for DPF operation and includes:

The DPF must be installed with all sensors replaced or reconnected as per manufacturer guidance to ensure accurate monitoring of pressure and temperature.

• Use original or certified parts compliant with emission standards
• Installation should be carried out in a garage specialized in exhaust systems
• Replace associated gaskets and clean related components such as catalytic converters if needed

Non-compliant fitting or removal of the DPF is illegal and may lead to emissions failure and engine warning lights.

A forced regeneration is an engine management process that raises the exhaust temperature to burn off accumulated soot quickly when normal passive regeneration has failed due to short trips or heavy soot load.

• It can be initiated via diagnostic tools or specific commands
• This process burns soot at around 600°C, restoring filter efficiency
• Regular forced regeneration can prevent DPF clogging and engine damage

Warning lights may reappear later indicating the need for another regeneration if driving conditions do not allow automatic cleaning.

To confirm if your vehicle still has the DPF installed and functioning:

• Check for soot deposits or black smoke at the exhaust pipe — absence might suggest removal
• Use OBD diagnostic tools to read DPF pressure and temperature sensors for data changes indicating its presence
• Inspect under the vehicle or consult vehicle documentation for part identification

Removing the DPF is illegal and can result in failing emissions tests and engine warning lights.