Το DPF δεν πρέπει να καταργείται γιατί συγκρατεί τα βλαβερά αιωρούμενα σωματίδια που δημιουργούνται από την καύση του πετρελαίου. Στον τέλος του καπναγωγού του λέβητα πετρελαίου έχω κάνει πατέντα παγίδα νερού που κατακρατή τα αιωρούμενα σωματίδια.  Δεν είναι μυστικό ότι το πετρέλαιο είναι βρώμικο καύσιμο. 

Αυτό ξερω και εγώ ότι γενικά κακο κάνει θα καταργουσα και το dpf απλά ειναι καθαρό και δεν χρειάζεται ακόμα 

Βρήκα αυτό στο youtube:       Κάνοντας μια περίληψη στο chatgpt, το βίντεο λέει τα εξής:   Here’s a summary of what “The TRUTH about EGR DELETES… Actual Science!” covers (where available), plus what scientific studies and technical sources say. If you want, I can also pull up specific numbers or quotes from the video. What EGR & EGR Delete Means EGR = Exhaust Gas Recirculation. It’s a system in petrol/gasoline & diesel engines that redirects (recirculates) a portion of the exhaust gas back into the intake. This lowers peak combustion temperatures, reduces oxygen concentration in the cylinder, and helps reduce NOₓ emissions. EGR Delete = Removing or disabling the EGR system (or its function) so that exhaust gases are no longer recirculated. This can be done physically (blocking valve/cooler) or via software. Key Points from the Video & Discussion From summaries and descriptions available online (“The TRUTH about EGR DELETES… Actual Science!” by Freedom Worx and related videos): Why people consider EGR deletes To reduce buildup/deposits in the intake system caused by EGR. To improve engine response, possibly power, under some conditions. To reduce some maintenance issues associated with EGR components (valves, coolers) getting clogged. Trade-offs / negatives Removing EGR typically increases NOₓ emissions. Because EGR’s main role is to suppress NOₓ by lowering combustion temperature and oxygen availability. The delete undoes that effect. Potentially worsened emissions of other pollutants (depending on how the delete is done and whether downstream systems compensate). Possible legal/regulatory risk: many jurisdictions require emission control systems to be intact and functional. Removing or disabling them often makes the vehicle non-compliant. Possible other side effects on engine operation: combustion temperatures might be higher, which could lead to more engine wear, higher thermal stresses, potential for knock in gasoline engines, etc. Interactions with other systems (e.g. DPF – diesel particulate filters) may be affected, potentially leading to clogging or forced regenerations. Where “science” comes in The video claims to look at measured effects (e.g. emissions, perhaps engine efficiency, fuel consumption) when comparing stock EGR vs deletes. It emphasizes that the effects vary depending on engine load, how much EGR was used, the design of the EGR/cooling system, and other emissions control/d aftertreatment systems. Overall conclusion The benefit of deleting EGR (in terms of performance or simplicity) is often outweighed by the emissions increases and potential engine or regulatory drawbacks. EGR is there for a reason; wholesale deletes are not “free of cost” even if people promote them that way. What Scientific / Technical Literature Confirms From engineering / peer-reviewed studies and technical guides: Effectiveness of EGR in reducing NOₓ — EGR is scientifically proven to significantly reduce NOₓ formation in both diesel and gasoline engines. By reducing peak combustion temperature and diluting the oxygen available.  Trade-offs & penalties: Increasing EGR rate tends to increase fuel consumption (worse BSFC – brake specific fuel consumption) under many conditions.  Particulate matter (soot) tends to increase with higher EGR because the combustion is cooler and less complete.  Also, lower temperatures and less oxygen can cause more unburnt hydrocarbons or CO under certain conditions. EGR rate and temperature matter: Not all EGR is equal. Studies show that the temperature and rate of EGR have big effects on emissions and efficiency. Cooler EGR can allow more recirculation with fewer side effects.  Engine design & aftertreatment systems make a difference: Whether the engine has a DPF, SCR (Selective Catalytic Reduction), oxidation catalysts, etc., changes how much harm or benefit an EGR delete will cause. If downstream systems are robust and emissions limits/enforcement are lenient, some of the adverse effects might be less visible.  Most Important Facts (Bring-Home Messages) NOₓ goes up: Delete EGR → more NOₓ emissions. This is the primary – and scientifically supported – downside. Fuel/ efficiency trade-offs are mixed: Sometimes, deleting EGR can reduce certain losses (like throttle losses in gasoline engines), but often these are offset by inefficiencies elsewhere (wasted heat, incomplete combustion, etc.). Particulate emissions & aftertreatment concerns: Without EGR, soot production can increase, which puts more demand on filters or causes them to clog prematurely. Legal & regulatory risk: Many jurisdictions treat removal of emission control systems as illegal. If you delete the EGR, you may fail inspections, get fines, or invalidate warranty/insurance. Engine longevity / damage risk: Increased internal temperatures, possible knocking, stress on components not designed for removed EGR, etc., may lead to wear or failures. Context is everything: The type of engine (diesel vs petrol), the emission standards in force, the presence of downstream emissions control (DPF, SCR), the driving pattern (city vs highway vs heavy load) all heavily influence how bad/good EGR delete will be.     Μετά από αυτό ρώτησα για το τι επιπτώσεις μπορεί να έχει σε ένα 2015 VW Polo 1.4 TDI να σβήσει κανείς την egr του. Η απάντησή του ήταν η εξής:   I couldn’t find any published scientific data specific to the 2015 VW Polo 1.4 TDI EGR delete (Euro standard) that gives exact numbers for NOₓ increase, fuel consumption changes, etc. But I found relevant studies and technical principles, plus data from similar vehicles, that let us make some educated estimates. Here are the findings + what likely would happen for your Polo. What we do know from studies NOₓ vs EGR rate Increasing the EGR rate reduces NOₓ emissions under most loads. DieselNet confirms that under all loads, more EGR = less NOₓ.  Conversely, deactivating or deleting EGR leads to increases in NOₓ emissions. A recent paper looked at a Euro-5 diesel with EGR manipulated and saw a measurable increase.  Fuel consumption & BSFC There is a trade-off: more EGR → tends to increase brake‐specific fuel consumption (i.e. less efficient) because the engine works with diluted intake air, lower combustion temperatures, etc.  However, when deleting EGR, people sometimes report better fuel efficiency in certain conditions—but this depends a lot on load, driving cycle, how clean the EGR + intake + turbo are, how well everything else is working.  Other penalties Increased thermal load / higher combustion temperature → potential for more engine wear.  More soot / particulate matter, since EGR helps “dilute” the combustion. Without it, soot may increase especially under light load or transient conditions.  Legal / emission test failure risk.  What might happen for a Polo 1.4 TDI (2015) with EGR delete Using the above, plus what’s typical in similar cars, here are likely effects you would see for that specific vehicle. Take these as estimates, not guarantees. Effect Likely Magnitude Conditions / Notes NOₓ emissions increase Large increase — possibly several times higher than stock under many circumstances. Could be 100-300% more depending on load / driving style. Especially under load, highway speeds, or where the engine would normally use high EGR rates. In city/transient driving, even more relative increase because EGR helps more in those situations. Fuel consumption (diesel used per km / mpg) Could slightly improve under some steady, high load / highway driving; or worsen under mixed / city / cold start / idling. The benefit might be small unless you also improve other related parts (intake, turbo, exhaust) and retune the ECU. Dirt / build up removal (if the stock EGR was clogged) may give some “restoration” effect. But in many real-life drives, fuel cost may go up slightly. Power & responsiveness Probably you’ll feel a bit more throttle response, less “smoky lag”, maybe slight gains in torque under certain conditions. But nothing dramatic unless you tune. If the ECU is still expecting EGR function and doesn’t adjust, you may get issues. Also, gains likely more noticeable in mid-range / high load rather than low RPM. Engine temps / wear Slight increase in temperature in combustion chamber / exhaust gases. Could lead over long term to more stress. Need good cooling, good oil, proper maintenance. Particulate / soot Increase, especially when driving in stop-go, cold, or low loads. Without EGR recirculation the cooling/dilution effect is gone, so unburnt hydrocarbons or soot can rise. How much depends on how clean the rest of the emission system is (filters, catalytic convertors etc.). What to Watch Out For, If You Consider Doing It Retuning the engine / ECU is almost mandatory. Just physically removing EGR without adjusting fuel maps / timing etc. may cause poor combustion, limp mode codes, etc. Risk of failing legal emission tests in Greece / EU. Euro-standards require emission control systems to be intact. Long-term durability issues: hotter combustion → risk to turbos, pistons, valves, etc. Effect on other emission devices (DPF, oxidation catalysts) may be negative: more soot might clog filters faster; sensors may see strange values.   Τέλος, ρώτησα τι κόστος έχει αυτό σε ένα χρόνο για κατανάλωση καυσίμου και συντήρηση. Πήρα την εξής απάντηση:   Nice — I ran numbers and pulled in up-to-date sources so you can see the likely real-world cost impact of an EGR delete on a VW Polo 1.4 TDI (2015) in Greece. I’ll keep it short and practical: Quick baseline (what a stock Polo 1.4 TDI typically uses today) Official / commonly reported combined consumption: ≈ 3.5–3.6 L/100 km.  Typical annual driving in Greece (useful national average to estimate yearly costs): ≈ 13,000 km / year.  Diesel retail price (mid-Sep 2025 Greece): ≈ €1.50–1.54 / L (I’ll use €1.52/L for the calc).  Using those numbers: Annual fuel use (stock): 13,000 km × 3.6 L/100 km = ≈ 468 L/year. Annual fuel cost (stock): 468 L × €1.52 = ≈ €711 / year. (All following numbers are estimates based on literature, workshops and typical parts/servicing prices — real results can vary by driving style, condition of engine/DPF, and whether the ECU is retuned.)  Scenarios after an EGR delete — fuel cost impact (plausible ranges) Scientific and field reports show EGR delete effects on fuel economy are mixed (depends on load, ECU tuning, cleanliness of intake/EGR prior to delete). Some drivers report slight gains at steady high load, others see no change or a small penalty in mixed/city driving.  I show three simple scenarios (percentage change on fuel use): Optimistic: fuel improves −5% (best-case retune / high-load driving) Fuel use = 468 × 0.95 ≈ 445 L → cost ≈ €676 (savings ≈ €35/year). Neutral: 0% change Fuel use = 468 L → cost ≈ €711 (no change). Pessimistic: fuel worsens +5% (more likely in mixed/city driving or colder conditions) Fuel use = 468 × 1.05 ≈ 492 L → cost ≈ €747 (extra ≈ €36/year). So fuel alone is unlikely to produce a large annual saving — you’re looking at tens of euros per year, not hundreds. (If you quoted a huge MPG improvement from some seller, that’s usually anecdote or achieved alongside other engine/turbo upgrades and ECU remap.)  Maintenance & repair cost risks (where the real money often goes) These are the areas where an EGR delete can cost you — and not just in euros, but also in legal/inspection risk: DPF cleaning/replacement: deleting EGR typically increases soot/PM production, which can force more frequent DPF regenerations, clogging, or earlier DPF cleaning/replacement. Cleaning typically costs €100–€400, while buying a new DPF (or a high-quality OE replacement) can be several hundred euros up to ~€800 for some models/brands. If delete increases DPF interventions even once every few years, annualized extra cost can easily be €40–€200 / year.  EGR / intake repairs: if you delete to avoid repeated EGR faults, note a replacement/major repair for EGR or associated parts on VWs can range widely; typical independent shop estimates for EGR valve replacement/cleaning run from ~€150 up to €400–€800 depending on parts & labour. If you remove EGR you may avoid an immediate repair bill — but if the delete is done poorly, other sensors will fault and you may still face repair bills.  Engine / turbo stress & oil: higher combustion temps and altered combustion can, over long term, slightly raise wear or stress on turbo/exhaust components — this is harder to quantify but can translate into earlier service costs (oil, turbo check/repair). Legal/inspection risk: in Greece / EU removing emission control devices is illegal. You could fail an MOT/emissions check, void warranties, or risk fines. Hard to put an exact €/year figure on that, but it’s potentially large (inspection failure causing mandatory repair bills + re-inspection fees). (See EGR role & regulation context.)  Emissions / environmental facts you should know EGR reduces NOₓ by lowering peak combustion temperatures; disabling it raises NOₓ substantially — multiple studies measured significant increases (sometimes hundreds of percent depending on the test/drive cycle). That’s the core environmental con.  More NOₓ + more soot means your car becomes dirtier for human health and urban air quality, and more likely to stress after-treatment systems (DPF / catalyst).  Bottom line — annualised cost comparison (summary) Baseline (stock) — €711 fuel / year (+ normal maintenance). With EGR delete: Best-case (fuel −5%, no extra DPF work): €676/year fuel → saves ≈ €35/yr but still illegal and raises NOₓ/soot. Likely case (0% fuel change) but + extra DPF cleaning once every 2–3 years (let’s say €200 extra every 3 years ≈ €67/yr): €711 + €67 ≈ €778/yr → cost ≈ +€67/yr.  Pessimistic (+5% fuel + earlier DPF replacement): €747 fuel + €200/year maintenance bump ≈ €947/yr → cost ≈ +€236/yr. So: small potential fuel savings (tens of euros) can easily be wiped out — and exceeded — by increased DPF/maintenance costs and legal/inspection problems. The environmentally harmful NOₓ increase is also guaranteed.  Recommendations (practical) If the reason you’re considering delete is clogging / reliability: first try proper cleaning (EGR + intake + intercooler) and DPF service — cheaper and legal. Cleaning EGR/intake costs are often far less than long-term penalties.  If you still want better driveability/power, consider a professional ECU remap + tailored intake / turbo health check rather than a straight EGR delete. A proper software approach can reduce negative side-effects. Don’t delete if you rely on passing inspections or want to avoid legal risk. In the EU it’s explicitly against rules to remove emission controls.