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I have an older diesel VW. It is extremely common for people to run tunes that disable the check engine light that is produced when you delete the exhaust gas r

I have an older diesel VW. It is extremely common for people to run tunes that disable the check engine light that is produced when you delete the exhaust gas recirculation valve (EGR), urea pump and diesel particulate filter (DPF). For things like the EGR, blocking it off is simply installing a bracket or two and closing off some vacuum lines. I can imagine people would simply reinstall this and swap the tune to pass and then immediately remove it after. In the US, for emissions, all you have to do is not run any check engine lights when at the test center which is easy to do in the software tune.

UncleEntity 8y ago
> In the US, for emissions, all you have to do is not run any check engine lights when at the test center which is easy to do in the software tune. Which is very disappointing... When I first moved to Arizona I had a '67 Galaxy and that thing got to run on the dyno in the emissions office but when I got my truck to replace it (not having AC in Arizona isn't fun) all they did was plug in into the computer and charge me more for the test. My (carburated) motorcycle was in between, they couldn't run it on the dyno and couldn't plug a computer into it so just tested it at idle -- which seemed pretty pointless to me, even being all hopped-up it still got better gas mileage than most cars on the road, though it did get pretty horrible gas mileage for a motorcycle considering I had to run premium in it.