Reader Question: Unfixing the “fix”?

Print Friendly, PDF & Email

Here’s the latest reader question, along with my reply!

Eric asks: Is it possible to buy one of the “fixed” VWs and then software-really-fix it back to get the 50 mpg?

My reply: It ought to be… My understanding is that the majority of the “fix” is a software/programming change. What can be programmed one way should be un-programmable… assuming that VW did not somehow lock down the car’s ECU, which is a distinct possibility.

I am going to try to suss out some more facts… stay tuned!

. . .

Got a question about cars – or anything else? Click on the “ask Eric” link and send ’em in!

If you like what you’ve found here please consider supporting EPautos. 

We depend on you to keep the wheels turning! 

Our donate button ishere.

 If you prefer not to use PayPal, our mailing address is:

721 Hummingbird Lane SE
Copper Hill, VA 24079

PS: EPautos stickers are free to those who sign up for a $5 or more monthly recurring donation to support EPautos, or for a one-time donation of $20 or more. (Please be sure to tell us you want a sticker – and also, provide an address, so we know where to mail the thing!)

My latest eBook is also available for your favorite price – free! Click here.  




  1. There are EGR delete kits for diesel powered vehicles (particularly for pickups). There were ones for the diesel VW cars before the scandal even. People do it to improve fuel economy, add horsepower, keep the engine cooler and prevent the extra wear and maintenance recent pollution controls require. It is (was) legal to remove the pollution controls for racing (off road).

    These kits remove the exhaust recirculation, both mechanically (the parts are physically removed) and software is changed so it still runs.

    Basically the modern way of pollution control is to mix the pollution particulates with the DEF fluid and to re-inject them into the engine with the diesel fuel to incinerate them during combustion. That’s why fuel economy and horsepower suffer, and the engine runs hotter, since its really not fuel but garbage disposal.

    So if the government inspects the vehicle often, its not really an option, since it’s not street “legal”. If its not inspected, you probably have a good chance you can get away with it.

    A software change should work. It would leave the car looking street legal (the DEF tank would still be there for example). I imagine the gains wouldn’t be as big since its not physically changed with only software changes. But if there aren’t many physical changes, you should get what it was before the “fix”. As long as there is no physical thing blocking a way to bypass the recirculation. That’s probably the big thing, I would guess the feds would want to make it harder to bypass it. Likely required a physical change to prevent easy bypassing.

    Another problem, someone has to reverse engineer the software, write replacement software that make the car still function. A big job with little payback, plus lots of potential legal problems (car companies like most software companies generally claim ownership of the software). When you get software (not just car software), your buying (or granted in the case of “free” software) a license for a copy, not ownership. You aren’t buying software, only writers of software own software.

    It’s probably the biggest reason there isn’t much in the way of customizing car software (it doesn’t help that few computer geeks like writing software for cars either). Up until software came, there has been tons of third party customization of cars.


Please enter your comment!
Please enter your name here