[christianchevell]

The most common CEL codes is what you should learn about. delayed response from the front o2s being moved back ( just that can be programmed out to not show a CEL), and the rear o2s should be just deleted in the tune and that's the most common as various codes can show from the rear o2s. You can get canned tunes for performance mods of course, yet your long tubes themselves could be frowned apon as voiding the warranty by a unscrupulous dealer. And yes a dyno tune is best but even more worth the price with more mods. You 5yr drivetrain warranty is most likely never going to be tested, its all up to you to decide.