Cold Air Intakes, what other things are needed after install if anything?

It will make it leaner, how much you won't know without wideband 02 monitoring. It may not be enough to be a concern, but in my case it was.

If you do run lean you have the Diablo Predator to help you out.

Cured completely with a custom Diablo tune

You can adjust them yourself, but you need a wideband 02 gauge/datalogger to do so. Dyno shops have them, or you can install one in your car as I did. They are relatively expensive compared to most other types of gauges.

You cannot adjust parameters on the Predator tuner itself to the degree that a custom tuner can with Diablo CMR software. For instance, say I had a lean spike in A/F ratio between 3500 and 4000 rpm. The Predator as it's delivered will only allow adjustments in two ranges, 2000-4000 and 4000-7000 rpm. If I richened up the ratio in the entire 2000-4000 range, I would now probably run rich between 2000 and 3500 rpm. A custom tuner with the CMR software on the other hand can adjust for much smaller rpm ranges, and target only the range that needs adjusting.