cummins cowboy

for those of us that have no local tuners around, I live in utah, most of the SC companies like kenne bell and saleen want you to run their canned tune, how trusting of a canned tune from these guys would you be?? do both companies canned tune produce the power they say it will?? also is there a way to double check without a dyno tune that your car is not running too lean and is safe running a particular tune.

Black GT

I don't know about their canned tunes, but Brenspeed's seem to be pretty good.

You can install a wideband Air-Fuel ratio gauge and keep track of it, and also do some data logging with handheld tuners such as the Xcal-2 using the A/F ratio as an input.