Purpose and Specifications

LIQUI MOLY 5171 Pro-Line Diesel Particulate Filter Purge is a 500ml cleaning fluid designed to flush and neutralize soot in clogged DPF units without removing them from your diesel vehicle. It dissolves tough contaminants after using the Pro-Line Diesel Particulate Filter Cleaner, restoring smooth engine performance, better fuel economy, and preventing costly DPF replacements that can run thousands of dollars.

Apply it through the sensor port using the DPF pressurized spray gun at 6-8 bar pressure in short 5-10 second bursts, then wait 10-15 minutes for it to distribute soot for burn-off during regeneration at exhaust temps over 550°C. One 500ml bottle cleans a full passenger car DPF, with regular use every 20,000-50,000 km or 12-24 months extending filter life significantly.

• Keeps DPF flowing freely for low fuel use and strong power
• No disassembly needed - quick workshop job under 1 hour
• Shelf life: 3-5 years stored cool and dry

When to Use / Replace?

Use LIQUI MOLY 5171 when your check engine light warns of DPF issues, power drops, or fuel use spikes - common after 100,000-150,000 km or frequent short trips under 20 minutes that block regeneration. Spray after cleaner to purge residues, then drive 20+ minutes or force regen with a scan tool. Replace DPF only if cleaning fails after 2-3 attempts, typically not needed with proper maintenance.

FAQ

Can I use this on my truck DPF? Best for passenger cars; trucks may need the separate Pro-Line Truck version for larger filters.

How often should I clean my DPF? Every 20,000-50,000 km or yearly if you do lots of city driving to avoid buildup.

Does it work on cold engines? DPF must be under 40°C before cleaning; warm up after for regen burn-off.