By on November 25, 2015


Volkswagen in Germany announced Wednesday its fix for millions of its 1.6- and 2-liter diesel engines in Europe that are illegally spewing nitrogen oxides and have cost the company billions in a massive worldwide scandal.

According to the automaker, a small “flow transformer” would be fitted in front of the air mass sensor in 1.6-liter, EA189 engines. The small transformer will calm air leaving the air filter before reaching the sensor. Volkswagen says the calmer air will allow the sensor to more accurately measure airflow for combustion. The fix would take less than an hour. For 2-liter engines, the proposed fix would be a software update and would take 30 minutes. Both plans have been approved by the German transportation authority.

Both fixes may be headed to cars in the U.S. However, the announced plan was in Germany for engines only on sale in most of Europe. Volkswagen submitted its U.S. plan last week to the Environmental Protection Agency and California Air Resources Board, but details of that plan haven’t been released.

Volkswagen said it would begin recalling cars in Europe in January, and that the recall would take roughly one year to complete.

According to the automaker, the performance of the affected cars would remain the same after the fix, but that testing had not yet been completed on those cars.

Volkswagen will submit next month its plan to fix 1.2-liter, three-cylinder engines fitted into its cars in Europe. The fix announced Wednesday will also apply to SEAT, Audi and Skoda vehicles fitted with the 1.6- and 2-liter engines.

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46 Comments on “Here Is The Fix For Volkswagens In Europe: A Mesh Air Pipe and Software...”

  • avatar

    That sounds like a pretty easy fix so the question is if it was that easy why did they not do it in the first place, I assume the US fix will be much harder because our rules are different.

    • 0 avatar

      Why didn’t they do it before? Why does any advance come later rather than sooner? There’s not been any advances in the basic technology behind the modern engine since ECU’s became the norm; it would have been theoretically possible to build nearly any engine today 20 years ago.

      Cheating on the software was probably easier than tying up compute clusters by running a bazillion different airflow models.

  • avatar

    If this fixes the problem in the US also (not totally optimistic there), color me impressed at their ability to come up with such a cheap fix.

  • avatar

    I have a hard time believing this actually fixes anything, if it were so simply why go through the headache of cheating in the first place? Why aren’t the rest of the manufacturers using this “mesh air pipe” instead of expensive UREA systems?

    I call BS

  • avatar

    I have a hard time believing this actually fixes anything, if it were so simple why go through the headache of cheating in the first place? Why aren’t the rest of the manufacturers using this “mesh air pipe” instead of expensive UREA systems?

    I call BS

    • 0 avatar

      I agree. Here’s my guess: Putting a “flow straightener” in front of the sensor so it gets a “more accurate reading” costs almost nothing, and gives VW an excuse for why the sensor was programmed to deliver illegal emissions performance when it worked as designed in the first place. They might as well have called it what it is: a “blame deflector.”

      They really should just give it up at this point. This is getting embarrassing to watch.

    • 0 avatar
      Dr. Doctor

      The baffles in the mesh pipe look like they’re going to cause laminar flow to smooth out and slow down the flow of intake air before it hits the mass airflow meter.

      Odds are that the flow straightener keeps intake airspeed roughly similar to that of dyno test conditions while the ECU update ensures that the engine stays in test mode.

      Why cheat? Because tooling, materials, and installation cost more money that a few lines of code to fool regulatory bodies.

  • avatar

    Sounds like vw has been shopping snake oil on the internet

    Looks like a hail Mary pass to me.

    • 0 avatar

      If only Billy Mays were still alive. He could save VW.

      “Hi, Billy Mays here with Volkswagen Mesh Pipe and Software Fix 2000! It’s the fast and easy way to clean up your TDI engine! Are you tired of your Jetta polluting like a bro’s 1996 Dodge Ram Diesel rolling coal? Well I have great news for you! Our brand new patented formula puts the CLEAN in clean diesel. For just $29.95, plus shipping and handling, you can say NO to NOx!

      BUT WAIT, there’s more. If you call in the next 10 minutes, we will double the offer! That’s right, just pay separate handling, and you can get two orders of Volkswagen Mesh Pipe and Software Fix 2000, for the low price of $29.95!

      Here’s how to order…”

  • avatar

    How has the issue “cost the company billions” already? I thought the cost wave is a future thing, in the form of recalls, goodwill goodies and, eventually, lost sales. The final one being an issue if anyone actually cared.

  • avatar

    Sounds like a nod and a wink to me. Or magic.

    If a flow straightener really works for the 1.6l EA189 diesel to meet Euro V, then the guy who thought it up should win the Nobel Prize for physics.

    Same for the programmer fixing the 2.0 liter, except he/she deserves the Nobel Prize for Literature.

    Where were these people when VW/Audi who designed this engine needed them back in 2007/8?

    Maybe they can add a G sensor or something to the EA288 to meet Euro VI, but it’ll just be software too, I bet, plus a free tanker load of AdBlue for each customer.

    Then they’ll be able to hire all the execs back from “vacation” and declare the US an outlier.

    • 0 avatar

      They would deserve those prizes if the engines got the same MPG and had the same power/drivability characteristics. They most likely get worse MPG and have less power/worse drivability after the fix.

      • 0 avatar

        Accurately measuring the airflow into a diesel engine which is basically unthrottled to begin with is, as others have said, needed to set the EGR levels.

        Whether the car is stationary or moving, a giant great air filter is interposed between the outside world and the intake manifold, so varying turbulence of air due to vehicle motion would hardly seem to be a problem.

        My honours program for my B Eng degree way back in 1969 involved designing a flow straightener only six inches long for air admission into a pipe. The air had to follow the classic flow profile for laminar flow within a foot of entry for the heat flow characteristics we were measuring. The pipe itself was over 20 feet long, and barely fit in the lab.

        We had plumbed the pipe airflow with a hot wire anemometer near the intake (a brand new Danish piece of kit whose brand name I forget – it cost $8K then which was a lot considering a new car was about $3K). The flow velocity was all over the place across the bore of the pipe, useless, the pipe was long, a flow straightener could only be 6 inches long because of room length.

        Luckily, having worked on fan-in-wing VTOL aircraft in a summer job the year before, where inlet performance was critical, I had an idea and it worked. Pretty near perfectly.

        So, knowing that these things can be designed is one thing. But in an engine intake, such precision is hardly needed. You measure over a broad range of flows and figure out a calibration, actual air volume in versus sensor voltage out and create a look-up table for the engine ECU. It ain’t rocket science.

        The Leeds University roadside NOx sniffer featured some weeks ago here on TTAC found VWs emit 5 to 7 times the legal limit. Folks, measuring intake airflow a bit better with a flow straightener is not going to fix that. You have only an NOx trap after the engine, a useless device only VW has used, and no SCR urea treatment, so no amount of software futzing around is going to make these engines legal just with a 29 cent piece of plastic.

        That’s why I say it’s magic and probably just fraud/deception. At least in the US, VW is going to be held to proper account and a piece of plastic is not going to “solve” the problem.

        Apparently though, VW is at least better at diesel engines than Opel and Renault judging by recent reports of those manufacturer’s NOx output levels. There, I believe no cheating is involved, just sheer, monumental incompetence.

  • avatar

    Keep in mind this is only to ix the lax European emission problems. US requirements are tougher.

    And also read the part where they re-program in addition to that flow straightener. so the engine may still use more recirculation, injection retardatation etc. to meet emission. therefore the loss in power and mileage still can happen.

    Satisfying European regulators probably is easy, VW is the largest OEM (too big to fail) and has the German government in it pockets.
    in addition now all the other diesels are proven to cheat, so they can’t punish VW only, but they can’t punish all of them. In Europe diesel is too big to fail…. all automakers depend on it.

    This flow-straightener sounds like one of those “improve your mileage” devices. Like putting magnets to your fuel lines, or making vortices in the air intake :)

    • 0 avatar
      heavy handle

      “this is only to ix the lax European emission problems”

      Exactly. The 1.6 wasn’t sold in the US, and it may technically have been compliant in the EU (their regs are really really lax). This is essentially a goodwill fix, or a “we’re doing something” fix.

      Anybody who extrapolates from this to a future US 2.0 Tdi fix is just guessing.

  • avatar

    I assume the flow straightener is 5% of the fix and the software is 95% of the fix.

    • 0 avatar

      I agree, pity it couldn’t be a software only solution from a labor/cost standpoint.

    • 0 avatar

      I agree, JMO. Except I think the software is 100% of the emissions fix, and the flow straightener is 95% of the PR fix.

      From a labor/cost standpoint, they didn’t need to do the flow straightener at all, which is why it had to be so simple and cheap. Its real purpose is to route bullshit. It’s a futile corporate attempt to obfuscate what everybody knows: that the whole problem was the deliberate programming of the software.

  • avatar
    Big Al From 'Murica

    We’re the tests that discoved the cheating in the first place done on a dyno? If so wouldn’t the air in the intake already be relatively “calm” compared to being on the road at speed? I guess we shall see.

    • 0 avatar
      Felis Concolor

      Precisely! This is the most transparent lie I’ve come across regarding the VW scandal.

      The only reason the mesh screen is placed before the MAF is to eliminate the “car is moving” data hash function which was a primary trigger for VW’s super lean cruise mode. Yes, an automobile’s computer can sort airflow data and determine if the MAF hash table matches a “car is moving” versus a “car is stationary with a big fan pushing air into it” mode.

    • 0 avatar

      No road testing was the way that the cheat was initially revealed though CARB and EPA have done their subsequent testing on a dyno. The issue is not a difference in the air flow because the vehicle is moving and there is no way to tell if the vehicle is moving through the MAF.

      On diesel engines the MAF is primarily there for determining the correct EGR flow. The typical MAF of today only samples a portion of the air flowing into the engine say 5%. It them determines the mass of air flowing through that portion where the sensing is done. The total mass of air is then extrapolated from this value. The air filter itself and the piping cause the turbulence that can cause different densities across the air stream. At different flow rates the turbulence likely changes causing the density difference across the stream to shift. So at one flow rate the meter may actually be seeing 5% of the mass and at another flow rate it is only seeing 4.5% or 5.5%.

      So to have accurate EGR flow calculations across all operating conditions they need accurate information from the MAF. Now it is possible to accurately model the system so that the calculations are corrected for the different air flow patterns. However that would take time and testing. By creating a choke point that equalizes air flow density throughout the stream they get better data w/o the need to have electronic means to compensate.

      The bigger issue is that they are reprogramming the computer to actually use EGR frequently enough and at the right rate to control emissions throughout the range of normal operation.

      Where I call BS is there claim that performance and mpg will be unchanged. The air flow device will almost certainly restrict peak air flow which certainly can limit peak power. EGR in the amount needed to properly control emissions will also tend to limit peak power as well as the thermal efficiency. Later injection timing is also one of the ways to limit NOx “in cylinder” but it too has both a power and efficiency penalty.

      Which of course is why virtually everyone else went to allowing the “in cylinder” NOx production to remain higher and clean it up through SCR.

      Of course DEF equipped VW’s have also been shown to fail but a SCR system only works effectively at the proper DEF flow rates. No or too little DEF for the conditions and the NOx will not be converted or a lot will pass through unconverted. DEF consumption will definitely increase on those vehicles once they fix them.

      • 0 avatar

        Very interesting and educational analysis, Scoutdude. I learned from it. Thanks.

        I assume your numerical example (5% vs. an unrestricted 4.5%-5.5%) was for illustrative purposes only. But it did set me to thinking that in cars with urea DEF injection, the improvement you’d get by regulating intake airflow to optimize the sensor would only be incremental. I don’t know how big the increment would really be, but when you’re talking about cars that were missing the legal standard by a factor of 9x, clearly the software adjustment of other engine parameters will be the vast majority of the fix. Which will mean you’re absolutely right that it has to hurt mileage and performance.

        • 0 avatar

          Yes those numbers were just for an example. Yes this is not going to fix the problem by itself. The bulk of the fix is going to be the software that actually runs the emissions strategy all the time. I think this will help since the goal is to add just enough EGR to meet the standard and not too much to minimize the impact on power and MPG.

    • 0 avatar

      The flow straightener is there so the cheating ECM thinks the car is on a dyno. ECM is reprogrammed so it meets Euro testing (now the car is always on a dyno). Once home the owner removed straightener, ECM sees there is no test, owner regains lost performance. Yes emissions go back up but now it is the owner who has tampered and VW meets the test requirements.

  • avatar

    This sounds like a move to get more accurate NOx readings, not something that will reduce NOx emissions.

    • 0 avatar

      I’d say it is just as they claim, to get more accurate information from the MAF, which will in turn allow them to better calculate the needed EGR flow. Too little EGR and NOx is high, too much EGR and power and efficiency suffer.

  • avatar

    The “flow straightener” makes me think “flux capacitor”… not real, but makes incredible results possible, while the audience temporarily suspends disbelief.
    Installing this bit of plastic will give the techs the opportunity to “update” the software while the car is in the shop with the hood open.

  • avatar

    Pre-MAF flow straighteners aren’t uncommon. The 1.8T in my Audi has one. A lot of people remove them to reduce restriction. It may very well improve the consistency of the MAF readings, though I’m fascinated as to how that will help.

    If they truly are able to retain performance with the related SW update, then that’s great. Somehow I do doubt it though.

    • 0 avatar

      It helps by suggesting that the cause of the problem, was that the decision making software was getting wrong readings, hence misbehaving. Rather than getting correct readings, but being intentionally coded to misbehave.

      A terrible higher order side effect of making everyone beholden to minute rules and regulations, is that decision making chains, even in engineering companies, become more and more stuffed with people whose skill is not engineering good solutions, but to “manage regulatory and pr issues.” It’s similar to why US companies are increasingly top stuffed with lawyers and finance yahoos: All potential income is allocated either politically/legally, or via Fed confiscation and redistribution.

      • 0 avatar
        Nick Engineer


        VAG has a strong culture of putting engineers into decision making positions. Even if, as you suggest, the decision chains at VW became more and more stuffed with non-engineers, at this point it is clear to everyone that whoever those non-engineering decision makers were, they have been and continue to be incredibly inept at managing the “regulatory and PR issues” stemming from this scandal.

      • 0 avatar

        stuki, I reject the underlying premise of your post.

        You’re saying there’s a lack of evidence that the cars were “being intentionally coded to misbehave.” This is clearly not the case.

        You then proceed from this flawed data point to the conclusion that the ultimate cause of VW’s problem was “a side effect of making everyone beholden to minute rules and regulations.” Massive damage to the air we breathe is not “minute,” and VW was anything but an unwitting victim of bureaucratic overreach — it was engaged in a conscious criminal conspiracy to break the law, on a massive scale that its main competitors proved was unnecessary.

        The propaganda that government is to blame for everything has become far too universally accepted. Believing that Big Lie has consequences that damage us all — like absolving a rogue automaker for an arrogant, reckless and illegal management decision it undertook with a clear understanding that it was breaking numerous nations’ laws and harming everyone for its own monetary profit.

  • avatar
    Nick Engineer

    I can only think of one way in which the airflow transformer will make a difference in how reliable the air sensor readings are: that they grossly neglected intake design thereby making air sensor readings unreliable, until now. This I find very hard to believe.

    This minor hardware change is a red herring.

    Changes on the engine tune will account for 95% or more of the emissions reduction they need to make. The flow transformer will only have marginal effect on emissions, maybe just the few extra points to barely get them under the euro 5 std. For US emissions good luck expecting that a flow transformer will somehow put back all the mileage and power loss that will result from the reflash.

    They could provide baby’s breath airflow to the engine and that won’t make the difference in how they manage emissions. It can’t have the multiplier effect they want everyone to believe.

    • 0 avatar

      They certainly could have adequately modeled the air flow to have accurate information from the MAF. Everyone else does it to get it it right for their gas powered cars. That is because the information from the MAF is the primary part of the fueling calculation.

      On a diesel the MAFs main purpose is to calculate the proper EGR flow to reduce emissions. If you aren’t planning on actually using the EGR in normal operation then you don’t need to have accurate air flow information. So why spend the time doing the proper modeling and development if they don’t need it since they are cheating.

      So to me it points to a wider range of people who knew about the cheat and adjusted their work accordingly.

      • 0 avatar
        Nick Engineer

        “So to me it points to a wider range of people who knew about the cheat and adjusted their work accordingly.”

        Exactly, I didn’t explicitly say it, and I am glad you did — more than coders would need to be involved to gloss over intake design.

        Regardless, during testing the air sensor got reliable enough airflow without a flow transformer to allow the ECM to operate the EGR effectively to reduce NOx.

        The next big giveaway will be if the associated parts start failing fast after the reflash. That would be a clear indication that most everyone in engine dev was aware they were cheating on the duty cycle of these parts and spec-ed cheaper ones that can’t hold up to constant activation.

        • 0 avatar

          Yes they did manage to get good enough data from the MAF to control NOx in the limited conditions that are seen in the EPA drive cycles. Those max load put on the engine in the drive cycles is relatively low when NOx is naturally lower.

  • avatar

    This device is strangely similar to the kind of automotive miracle cure devices which used to fill the back pages of a JC Whitney catalog.

  • avatar

    It remains mind blowing to me the free ride that Takata is getting in the media compared to other automotive scandals.

    …”There have been instances in the past when Takata provided inflater validation testing reports to automotive customers that contained selective, incomplete or inaccurate data,” a Takata spokesperson admitted. “These lapses were and are totally incompatible with Takata’s engineering standards and protocols, and we sincerely apologize to our customers, our regulators and the driving public…”

    Last count I saw was up to 34 million vehicles impacted worldwide with a failure rate pushing 2%. That means there are 680,000 Claymore mines in the dashboards and/or steering wheels of cars out there.

    I can take out the floor mat in a Toyota – problem solved.

    I can remove all the crap hanging off my ignition switch key in a GM product – problem solved.

    I can inflate the tires properly in my Ford – older historical problem solved.

    I can’t fix my diesel VW – but it isn’t going to directly potentially kill me while driving.

    I can’t fix my Takata equipped vehicle, and I can’t deactivate the airbag, and if it goes off in an accident – a 1.5% to 2% chance it will actually kill me.

    Ya I know, suppliers fleeing them and they will likely go out of business, which bodes so well for the victims when no one is around to payout the settlements. Bankruptcy restructuring and a company name change makes the liability go away, and keeps the leaders making airbags.

  • avatar

    What a load of BS….

    “Oh look, Zir, ve have fixed it like it vasn’t broken.”

    That tells you who runs Europe.

    Guten Tag.

  • avatar

    Translation from Winterkornese into English is as follows:

    A Mesh Air-pipe & Software = no fix at all
    VW has some set of tailpipes offering this BS up as a fix.

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