Tried to stick a computer back in the truck that was not changed but reflashed cranks but no start. The truck is a 2003 z71 Silverado with a 5.3. Currently ripping the O?S with lsDroid. The truck would run with the computer that came in it when I bought it but runs richer than a can of corn and gets like half a mile per gallon. OS # READS 12579405, checked my recent bins and that os is 03 2500 6.0 lq4 2wd in the bin/xdf that i have for that OS. The question is though how did it even start before with that computer and cranks but no start with this other one,. Maybe i made a brick out of the p59 12597120 that I flashed here. My Volvo runs like a champ though throws a couple trans, an air and a fuel tank pessure code, might try that ecu in the truck but the flash is with a 4l80e so better leave that alone.