I recently had to test my truck, what a joke.
I left it the way it is, they said electronic mod's are no longer allowed. They let it go since you can turn the comp off, but warned me not to use it on public roads :-laf .
Here, they test on a dyno, or what pretends to be a dyno. One strap from my reciever to the ground is all they used, truck made more tire smoke than anything when they applied the load to it. Luckily, the guy just backed off the throttle to keep the tires from spinning and by doing that it didn't smoke much out the pipe. Passed with flying colors

. $65 down the drain, along with another $500 for a new sticker.
The good news is, at the moment the plan is to end all emissions by 2007. There is no plan for a new emission test as of now. However, Larimer county alone did $6 million in emmission tests last year, so of course all the test locations are crying about losing the requirement to register.
Matt