[dpaul]

There are free backend flashes on N54tech.com designed for different fuels, if that's what you mean. If you mean which JB4 MAP, my answer would be the most aggressive one that doesn't give significant timing pulls. The one good thing about JB4 (from my limited perspective) is the ease with which it lets you customize boost profiles (MAP 7, if I remember correctly). Basically same answer as above; try a map, make some logs and keep going until something doesn't look right.

There is a reason not to leave the DP fix installed - basically that the pre-cat sensors use the output of the post-cat sensors as a calibration standard and the DP fix alters that output to fool the DME about cat efficiency without taking the calibration function into account. Furthermore, it spoofs bank2 sensor output from bank1 so there is no actually reporting from bank 2 at all. I can go on about this if you really care. The DP fix is nothing more complex than a voltage divider so the post-cat voltage is always too low. One presumes the DME can look at the shape of the post-cat voltage response to different conditions and adjust its calibration routines but who knows.

Anyway, pretty much anyone connected with Burger will tell you to remove the thing, and they were doing that well before they got so concerned about the legal issues. But you'd be best off to do your own reading and make your own decision. Just because something has been brought to market doesn't mean it is either safe or effective, particularly something designed to circumvent existing federal law..