Renault Laguna Diesel Particulate Filter DPF

The Diesel Particulate Filter (DPF) on Renault Laguna diesel models, especially Laguna III with 1.5 dCi K9K or 2.0 dCi engines, captures soot particles from exhaust gases. It regenerates by post-injection of diesel fuel to reach temperatures above 600°C. This is achieved by a 5th injector located between the catalytic converter and the DPF. The system monitors soot load via differential pressure and temperature sensors, designed for Euro 5 engines like the K9K 782.

Regeneration is mainly automatic: when soot load is high, the engine's ECU triggers post-injection of diesel into the exhaust (not into the combustion chamber to avoid oil dilution). This raises the exhaust temperature to over 600°C, burning off soot until pressure differential returns to normal. Forced regeneration can be performed via a diagnostic tool, clearing fault codes after sensor and injector checks.

Common symptoms include warning lights such as "Injection to Check," "Anti-pollution," or DPF lights ON, injector safety mode, and trouble codes like P242F, P2002, or P1525. Frequent causes and solutions are:

• Cracked or damaged pressure sensor hoses: Heat from regeneration degrades hoses causing false sensor signals. Solution: Replace hoses (~6€ DIY) and reposition sensors.
• Faulty 5th injector: Causes recurring blockage. Solution: Remove, clean or replace injector and gasket.
• Faulty injection ECU strategy (code P200292): Solution: Perform forced DPF regeneration and ECU reprogramming with Renault.Net or DVD ≥108.
• Main injectors dirty: Leads to low exhaust temperatures. Solution: Use diesel injector cleaner additives and DPF regenerants.

Other causes include accumulated non-burnable ashes and frequent short trips preventing passive regeneration.

DPF systems are found on the following models and engines:

• Laguna III (2007-2015) with 1.5 dCi (K9K 782) and 2.0 dCi (DT0/DT1) Euro 5 engines.
• Laguna II and Laguna III phase 2 with integrated 2.0 dCi DPF exhaust systems.

DPF is a mandatory anti-pollution component for diesel cars post-2005 to reduce fine particulate emissions.

Maintenance and cleaning options include:

• Using fuel additives such as diesel injector cleaners and specific DPF regenerants (e.g. Wynn's products) to improve injector and filter performance.
• Performing forced DPF regeneration using a compatible diagnostic tool.
• Professional DPF cleaning services available at automotive workshops.

Regular motorway driving helps ensure passive regeneration of the DPF.

Before replacement, thoroughly check the following to avoid unnecessary costs:

• Integrity of pressure sensor hoses, replacing any cracked or burnt hoses.
• Functionality of the 5th injector and main injectors.
• Performing forced regeneration to clear soot before deciding on replacement.
• Diagnosing and fixing injection system errors (ECU codes).

DPF replacement can be costly and should be a last resort after all checks and cleaning attempts.

While some aftermarket forums discuss DPF removal kits and deletion, it is strongly discouraged because:

• It is illegal and may cause failure in pollution and technical inspections.
• Increases pollution due to particulate emissions.
• May cause engine management issues and degrade performance over time.

Maintaining or properly servicing the DPF is recommended rather than removal.

Krosfou supplies new, high-performance DPFs for Renault Laguna. These are original new products, not reconditioned or refurbished parts, manufactured in Europe with high-quality ceramics and INOX 409 stainless steel.

Krosfou’s DPFs are certified by TÜV SÜD Automotive and come with a 3-year warranty covering up to 100,000 km usage. The products meet or exceed manufacturer specifications and comply with European anti-pollution regulations, providing durable and efficient filtration performance.

Ordering Krosfou DPFs includes direct factory support, free returns within 30 days for unused parts, and expert technical assistance to ensure correct compatibility and installation.