Tag Archives: UK motoring

What’s the difference between DPF and catalytic converter?

July 15, 2025 Alex Leave a comment

Quick answer

A DPF captures and burns soot particles in diesel exhaust, while a catalytic converter reduces gases like CO and NOx. Both are part of emissions control, but serve distinct functions. Petrol and diesel vehicles typically have catalytic converters, whereas DPFs are specific to diesels.

Detailed answer

Emissions technologies can be confusing, so let’s break it down:

1. The Diesel Particulate Filter (DPF)
– Purpose: Traps and stores carbon-based particulates (soot) in diesel engines, periodically regenerating (burning them off) to reduce visible smoke and harmful particulate emissions.
– Location: Typically installed along the exhaust system in a diesel vehicle, often after the catalytic converter.
– Regeneration: The filter must periodically heat to incinerate the trapped soot. This keeps the exhaust path clear.
– Who Has It: Almost exclusively diesel vehicles. Petrol engines generally don’t produce enough soot to require a DPF (though some modern direct-injection petrols use a GPF—Gasoline Particulate Filter—but that’s separate).

2. The Catalytic Converter
– Purpose: Converts toxic gases—like carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx)—into less harmful substances (CO2, water vapor, nitrogen) using precious metal catalysts (platinum, palladium, rhodium).
– Location: Placed in the exhaust manifold or downpipe, so hot exhaust gases pass through the catalyst early. This is key for efficient chemical reactions.
– Operation: No “storage” cycle like a DPF. It’s a continuous chemical reaction as the exhaust flows through.
– Who Has It: Petrol and diesel vehicles both use catalytic converters (though diesel cats differ slightly in design). They’ve been mandatory in many places since the 1990s.

3. Combined Systems
Modern diesel cars usually have both a catalytic converter (to reduce NOx and other gases) and a DPF (to trap particles). After the catalytic converter handles the gaseous pollutants, the exhaust moves on to the DPF to remove soot. Each device addresses separate pollution challenges.

4. Maintenance Differences
– DPF: Risk of clogging with soot if insufficiently heated or short-tripped. Requires regeneration cycles or cleaning.
– Catalytic Converter: Less prone to physical clogging, but can degrade over time or be contaminated by leaded fuels, oils, or coolant. Replacement can be costly if the precious metals degrade.

5. Legalities
Removing or tampering with either device is typically illegal, leading to MOT fails and fines. Catalytic converters also face theft due to valuable metals. Meanwhile, DPF deletes degrade particulate emission compliance.

6. Big Picture
Both are crucial for meeting emissions standards, but they tackle different pollutants:
– DPF: Captures physical soot/particles.
– Catalytic Converter: Converts harmful gases into safer byproducts.

If you drive a modern diesel, you almost certainly have both. If it’s petrol, you’ll have a catalytic converter but no DPF unless it’s a direct-injection model with a GPF. In any case, these components collectively help vehicles pass emission tests and keep our air a bit cleaner.

In short, the DPF deals with solid particulates (soot) in diesel exhaust, while the catalytic converter handles gaseous emissions like NOx and CO in both diesel and petrol vehicles. They serve complementary roles, each tackling a distinct part of exhaust pollution.

Diesel Particulate Filters (DPF)

Nissan Qashqai / Juke / X-Trail DPF: sensor location, cleaning, regeneration?

July 15, 2025 Alex Leave a comment

Quick answer

Most Nissan Qashqai, Juke, and X-Trail diesel DPF sensors are near the filter with pressure hoses attached. Regular cleaning or forced regen can clear blockages. The car triggers active regens during motorway runs, but short trips may require manual intervention.

Detailed answer

Nissan’s popular diesel crossovers—the Qashqai, Juke, and X-Trail—feature DPF setups that help reduce particulate emissions. Their DPF location is usually close to the engine’s exhaust manifold or under the floor, with a differential pressure sensor tracking soot load. This sensor typically has two small hoses: one before the filter and one after, allowing the ECU to gauge pressure differences.

Sensor Location: Pop the bonnet and look toward the exhaust side. You’ll often spot a sensor bolted to the bulkhead or a bracket near the filter. The hoses might be rubber or silicone lines feeding the sensor. If these hoses crack or become blocked with soot, the sensor can give misleading readings.

Cleaning:
– Additive: Some owners try in-tank DPF cleaners that lower soot burn temperature.
– Spray foam: For mild blockages, removing a sensor or a bung can let you inject foam to loosen soot.
– Professional service: A shop can remove the DPF, use chemicals or a cleaning machine, and reinstall it.

Regeneration: Nissan’s ECU attempts active regens when the filter hits a certain soot threshold. This demands stable driving conditions at moderate to high RPM for 10–20 minutes. If you do short journeys, the cycle might never complete, leading to repeated warnings.

When the dashboard throws a DPF or engine light, you might need a forced regen using diagnostic tools. A mechanic revs the engine while parked, spiking exhaust temperature to incinerate soot. Alternatively, a good motorway run at 2,500+ RPM might do it—assuming the ECU sees fit to trigger the cycle.

Common Problems:
1. Short-Trip Clogs: City dwellers who rarely stretch the vehicle’s legs.
2. Sensor or Hose Faults: If the pressure sensor or its pipes fail, the ECU can’t track the DPF’s status accurately.
3. Residual Ash: Over time, the filter collects non-burnable ash (from oil, etc.) requiring deeper cleaning.

Tips for Nissan Diesel Owners:
– Periodically drive 15–30 minutes on a motorway at steady revs. That helps the ECU run a full regen cycle.
– Use the correct low-ash oil to reduce residue buildup.
– If warning lights persist, scan for error codes. It could indicate sensor or EGR problems creating excess soot.

When the filter is heavily blocked, limp mode can strike, limiting power. Don’t ignore it. Forced regen or a professional cleaning can restore normal function and protect the turbo from damage. Nissan’s DPF system generally works well if you maintain it and allow regeneration. With a bit of care—like checking sensors, letting regens finish, and using quality oil—you’ll keep your Qashqai, Juke, or X-Trail’s DPF in good shape for miles to come.

Diesel Particulate Filters (DPF)

DPF pressure sensor location?

July 15, 2025 Alex Leave a comment

Quick answer

Typically mounted in the engine bay or near the DPF, it’s connected by small hoses to the filter. One hose reads pre-DPF pressure, the other post-DPF. Exact placement varies by vehicle model.

Detailed answer

In a Diesel Particulate Filter system, the differential pressure sensor is crucial for measuring how much soot is clogging the filter. Locating it can be confusing if you’re peering into the engine bay for the first time. Here’s what to look for:

1. Physical Description
Often a small, rectangular or squarish plastic unit with an electrical connector. Two short rubber or silicone hoses attach to the sensor—labeled or color-coded for “upstream” and “downstream” relative to the DPF. The sensor itself might have a mounting bracket or a couple of bolts holding it in place.

2. Typical Placement
– Engine Bay Near Firewall (Bulkhead): Many manufacturers place the sensor high up, away from direct exhaust heat but still close enough to link with hoses. You might spot it on or near a bracket attached to the firewall or inner fender.
– Close to the DPF: In some designs, the sensor sits under the car, not far from the filter itself. The logic is to keep the hoses shorter. But this location can subject the sensor to road grime or moisture.

3. Hoses Leading to the DPF
One hose taps into the exhaust pipe before the DPF, measuring “inlet” pressure. The other connects after the DPF, measuring “outlet” pressure. The sensor compares these two readings—if the difference is too high, the ECU deduces soot buildup.

4. Checking the Manual
Your vehicle handbook or a workshop manual often shows a diagram of the DPF layout and sensor routing. If you’re unsure, consult official diagrams to ensure you’re looking at the correct component. Some cars also have multiple sensors, including temperature probes around the DPF.

5. Why Location Matters
If you’re troubleshooting DPF faults (like code P2452 for a sensor issue), you may need to inspect hoses for cracks or blockages, or test the sensor’s electrical readings. Knowing where it sits can save time. Also, some owners add a gauge to read the differential pressure—useful for diagnosing partial blockages.

6. Common Maintenance
Make sure the hoses remain free of soot or condensation. In rare cases, the sensor itself might clog, or moisture can freeze in the line during cold weather. Replacements typically cost tens to low hundreds of pounds. If the sensor fails, the ECU might not trigger regens properly, leading to a clogged DPF.

Conclusion
Finding the DPF pressure sensor typically involves looking for a small plastic sensor with two hoses connected—one from before the DPF, one from after—either near the engine bay firewall or close to the filter. Checking vehicle-specific diagrams helps pinpoint it quickly. Maintaining clear hoses and a functional sensor ensures accurate soot load readings, letting your DPF system regenerate at the right times.

Diesel Particulate Filters (DPF)

How to do a forced DPF regeneration?

July 15, 2025 Alex Leave a comment

Quick answer

A forced DPF regen often requires a diagnostic tool that triggers high exhaust temperatures to burn off soot. Mechanics connect to the ECU, set the car to a specific mode, then run the engine at elevated RPM until the filter is clear.

Detailed answer

A forced or “manual” DPF regeneration is a procedure used when normal, passive or active regeneration isn’t cutting it. If your filter is so choked with soot that standard on-road regens fail, a forced approach can save you from total blockage—or an expensive new filter. Here’s the general rundown:

1. Acquire the correct diagnostic equipment: This typically isn’t a job for random phone apps. Professional-grade scan tools or manufacturer-specific software can talk directly to your car’s ECU. Mechanics often have these devices on hand.

2. Check engine prerequisites: Make sure there are no underlying faults that could hinder regeneration, like temperature sensor errors or glow plug issues. The oil and coolant levels should be correct, because the engine will be revved for a sustained period.

3. Connect and initiate: Hook up the scan tool, navigate to the DPF or “service regen” menu, and select “forced regeneration.” The car’s ECU will confirm you meet certain conditions (engine warm, no major fault codes, etc.) before proceeding.

4. Rev and monitor: During forced regen, the ECU keeps the engine at a high idle or instructs you to hold certain revs. Exhaust temperatures shoot up—often over 600°C—to burn off the soot. It can take 10–30 minutes depending on how clogged the DPF is.

5. Observe for unusual signs: White or grey smoke may appear at the tailpipe as soot burns away. Keep an eye on coolant temps, and ensure your cooling fans run. If anything seems amiss (like excessive smoking or abnormal engine noises), stop the process.

6. Completion: Once the scan tool indicates success or you see the DPF load drop, the forced regen is done. The warning light might switch off, and your soot load reading should be significantly reduced.

Some cars allow for a forced regen by pressing a sequence of pedals or buttons, but that’s less common. More frequently, you’ll need that special diagnostic kit. Because this procedure can push your engine to high stress levels, many owners prefer a professional’s help. Also, forced regen isn’t a routine fix. If your DPF repeatedly needs it, investigate the root cause—are you only driving short distances? Using low-quality fuel? Neglecting oil changes?

In daily life, your car should manage active or passive regenerations on its own. Passive regen occurs during motorway journeys at constant higher RPM; active regen is triggered by the ECU when soot buildup reaches a certain threshold. Forced regen is like an emergency measure.

Finally, never force a regen if your DPF is physically damaged or you have major mechanical problems. That could make matters worse. A quick inspection or a chat with your mechanic will clarify if forced regen is appropriate. If done correctly, it can restore normal flow, keep that DPF happy, and let you drive on without that dreaded limp mode or DPF light glaring at you.

Diesel Particulate Filters (DPF)

How to force DPF regeneration Mercedes Sprinter?

July 15, 2025 Alex Leave a comment

Quick answer

Forcing a DPF regen on a Sprinter often needs a diagnostic tool to activate “Service Regeneration” mode. The van is set to elevated revs while stationary or on a test drive. Ensure no fault codes block regen, and monitor temperatures closely.

Detailed answer

If your Mercedes Sprinter’s Diesel Particulate Filter (DPF) is clogged, you might see a dash warning, reduced power, or higher fuel consumption. Sometimes a manual or “forced” regeneration is necessary, particularly when regular driving conditions won’t initiate an automatic burn-off. Here’s a brief guide:

1. Diagnose First
Use a scan tool or diagnostic software capable of reading Mercedes-specific codes. Look for any stored fault codes—like EGR or temperature sensor errors—that might prevent regeneration. If the ECU sees a major fault, it won’t start a regen. Address those issues before proceeding.

2. Ensure Safe Conditions
A forced regen elevates exhaust temperatures to hundreds of degrees Celsius. Perform it in a well-ventilated area, away from flammables. Keep a fire extinguisher at hand, just in case. The vehicle might need to idle at 2,000+ RPM for a set duration.

3. Use the Right Tool
Mercedes Sprinters often require a professional-level scan tool (e.g., Star Diagnostics) or a reputable aftermarket equivalent. On the device’s menu, locate something like “DPF Service Regen” or “Diesel Particulate Filter Regeneration.” Follow the on-screen prompts.

4. Elevated Revs
During forced regen, the ECU holds the engine at a specific RPM (often around 2,500) for 10–20 minutes, raising exhaust temps to burn off soot. The tool may show progress or ask you to maintain certain conditions—like no pressing the accelerator or keeping the engine at a set load.

5. Watch Temperatures and Warnings
Monitor coolant and exhaust temps. If you see abnormal temperature spikes or error messages, abort the procedure. Sometimes the DPF is too clogged for a forced regen, requiring off-vehicle cleaning or replacement.

6. Completion
Once the scan tool says regeneration is finished, or the soot load reading drops significantly, the process is done. You might see some smoke or smell as burned-off deposits exit the exhaust. Clear any remaining codes. If your dash lights stay off and performance improves, you’re good to go.

7. Road Test
Take the van for a test drive. Observe if power is back to normal and if any dash lights reappear. A successful forced regen often restores driveability. However, repeated forced regens aren’t a long-term fix if your usage pattern (short deliveries, constant stop-start) constantly clogs the DPF. Consider scheduling occasional longer runs or investigating mechanical faults that produce excess soot.

Tips
– If you lack advanced tools, consider a specialist or a Mercedes dealer. They have official Star Diagnostics.
– Always use the correct engine oil (low SAPS) to minimize DPF blockages.
– Forced regen is typically a last resort. If it fails or the DPF is physically damaged, cleaning or replacement is next.

So, to force DPF regeneration on your Mercedes Sprinter, you’ll need a proper scan tool and a safe space to run the engine at elevated revs under the ECU’s command. Address any underlying errors beforehand, let the tool guide you through the process, and keep a watchful eye on temperatures. Done right, your van’s DPF can breathe easy again, allowing normal operation without the dreaded warning lights.

Diesel Particulate Filters (DPF)

Peugeot 3008 / 308 / Partner DPF fluid refill, additive location?

July 15, 2025 Alex Leave a comment

Quick answer

Many Peugeot models use an onboard additive (Eolys fluid) stored in a small tank near the fuel tank or rear axle. When low, you’ll see a dash alert. A refill can cost around £100–£200 at a garage, plus labour.

Detailed answer

Peugeot’s 3008, 308, and Partner diesel models commonly employ a special fluid, often referred to as Eolys, to assist with DPF regenerations. This fluid mixes with the fuel to lower soot’s ignition temperature, making regeneration easier. Over time, the reservoir depletes, typically after 60,000 to 80,000 miles, depending on driving conditions.

Where’s it located? Usually, the additive tank or pouch is close to the main fuel tank, either under the car or near the rear axle area. Some models have a rigid plastic tank, while others use a flexible pouch. Access might require removing a shield or wheel arch liner.

Refill process:
1. Diagnosis: A dash warning might read “Diesel Additive Minimum Level” or similar. Check your manual or scan tool to confirm.
2. Access the tank: Raise the car or use ramps for better undercarriage access. You may need basic tools to remove protective covers.
3. Refill: Use only the correct Eolys fluid recommended by Peugeot. The fluid type can vary (Eolys DPX 42, Eolys Powerflex, etc.) depending on your car’s year. A typical refill volume is 1–3 litres.
4. Reset the additive counter: The car’s ECU tracks fluid usage, so you must reset it via a diagnostic tool or the manufacturer’s software. If you skip this, the warning may remain.

A garage typically charges £100–£200 or more, covering both the fluid and labour. DIY is possible, but you still need a proper scan tool to reset the system. If you ignore a low additive alert, the DPF can clog sooner, and you’ll risk bigger bills or limp mode.

Common pitfalls:
– Mixing the wrong fluid can damage the system or hamper regeneration.
– Failing to reset the additive counter leads to persistent dash warnings or incorrect dosing.
– If you run out of additive completely, your filter might not regenerate at all, hastening blockages.

Peugeot’s approach to DPFs is slightly different than some other automakers that rely purely on passive and active regens. Eolys fluid helps burn off soot at lower temperatures, ideal for city drivers who don’t always reach high motorway temps. But it means an extra step: additive refills.

So, for a Peugeot 3008, 308, or Partner, keep an eye on that additive level warning. If you see it, don’t delay. Topping up the correct Eolys fluid and resetting the counter promptly can keep your DPF happy and avoid bigger headaches. Do it yourself if you’re comfortable working underneath the car and handling diagnostic tools, or let a qualified mechanic handle it for peace of mind.

Contact us

Find us on:

Newsletter