96 vortec 305 missing under a load

[Jeremy69]

Hey guys, I've tried searching for a solution to my problem but can't find exactly what i am looking for. Ive got a 96 with a vortec 305 that is missing and studdering under regular driving load. seems to idle fine but won't Rev higher than 3k. I have replaced the rotor, cap, wires, coil, etc sensor alternator (un related), fuel pump which had a ground issue (fixed), fuel filter, mass air and I think thats it so far. It was throwing multiple misfire codes and ETC codes. after replacing the ETC sensor, the problem is still happening. I havent checked the codes again because I dont have a personal scanner and I dont trust it to get far from the house after leaving me stranded. Any ideas would help. Thanks