1994 Z28 stock with hooker catback and electric cutout, when I get on it and hit WOT, it almost seems like it's missing. I can't really explain it, RPMs drop by about 500 and it repeats 5-6 times until it finally "catches" you might say, and runs alright. I don't know if it's RPM related, speed related, or throttle related. If I get a log with freescan, will you guys analyze it and let me know what it might be?

[Edit]
Guess I should add, new plugs and wires and coil as of 4k miles ago. Also, no SES except code 83 which apparently is something to do with the torque converter? New fuel filter, too.

 

sounds like the opti to me. im having a similar problem where around 5000rpm it sputters and bogs. im thinking its the opti, were they vented in 1994? i know mines not. if it isint i would especially say its probably that