i've got an 01 cummins 2500 and a few people told me theres a way to blow smoke out my stacks without a computer box they said something about a blow by valve i would just like to see smoke come out without having a computer box and messing up my tranny is there any possible way

 

only my opinion, why are poeple so interested in smoke?? you do realise it is unburnt fuel and while you are blowing smoke you are spiking your egts, which if not monitored will melt down a piston or two over time... you do have gauges right?
Do a search for "smoke switch" and see what you come up with.

 

To anwer your ?, no you have to have more fuel to get smoke, and on a 24v truck the only way is a programer or injectors. and the smoke switch only works with a wire tap box like a edge comp.