If you're getting a CEL after stage two that isn't the tune. These tunes actually remove and prevent several CELs associated with readiness which are needed to pass emissions in several states.
Unless they changed things, the tunes remove the CEL by bypassing the readiness checks, which then flags in the emissions test as "not set". They do not "remove" the CEL, they prevent them from being set and yes there is a big difference.
Now some states will allow you to pass with one readiness check unset but not sure if they allow 2, and many states will not allow it at all.
This makes no sense, if emissions was the reason how are they selling Stg 3 kits? If the standard disclaimer that the software and equipment are not for highway use is enough for the Stg 3 why not the Stg2?
There's something missing here, or someone is way late on their April Fool's joke.