well two weeks ago i got home in my firebird and parked it in my driveway,Went back out to move the car and it would start but ran like S/'#t not throwing codes missing bad,went thru usual check list,check spark it is very intermittent good on some cylinders bad on others, checked coil pack with another set of coil packs,changed plugs,Checked fuses,checked power at coil packs,Checked grounds at coil packs,changed back to stock injectors to make sure one wasnt hung open then changed them back,checked compression,Rockers,pushrods,switched out Crank postion sensor,Cam position sensor,Pulled wiring harness out of car took all black tubing off and went thru every wire verifying no broken connections and or grounds to and from there destinations,Removed all unsed wires from harness EGR,Rear O2s,ETC.,Still wont run right?,Must be the PCM right?,Okay brother works at salvage yard get Computer out of a running 1999 chevy silverado book says they are same computer just have to reflash it,So after i purchase the Silverado credits so i can flash my running great firebird tune to new computer i do a write entire and when done i shut off key for ten or so seconds then try to start,IT cranks but now wont even make a pop nothing? okay i am very stumped.What now??