i have a 94 z28 5.7 it was missing so i changed the cap and rotor
now to get it to start i have to have to have the peddle to the floor and when i do that the cat is only at 400 rpm the gas is at 38 psi

 

You should have changed the entire opti. However, before doing that, check that everything has been put back properly; that includes the rotor, cap and wires.

 

i checked and checked again that everything is back in proper place i changed coil already that was no help. im going to change the plugs and wires tomorrow if i get done working before 5 and not raining

 

If the opti was the cause of the miss to begin with, a cap & rotor isn't always a guaranteed fix. Sometimes the optical reader inside the opti gets crapped up, and messes up the ignition signal. If that was the problem originally, then you still have that problem. Are you possibly getting a check engine code?

 

Do you know what was causing the miss in the first place? Did you replace the plugs and wires yet? My car has a miss(not that bad) espicially when i start it i have to feather the throttle a little and i already replaced plugs, wires, cap, and rotor with no improvements so...