Well I am having the random misfire code like I have read about here on the forums and have change everything I have seen all you post now Im lost

Changed
map sensor
fuel injectors(spider)
plugs and wires
distributor and rotor
tps sensor
O2 sensors

What else could it be??? please help me

 

woops sorry 2001 blazer 4wd 4.3 l vortec

 

Do you have access to a scan tool with data? If so I would check to see which cylinders were missing, and then go from there. If the truck funs good with no noticable miss, it could be a vacuum leak, but you can try cleaning your MAF also. HTH