Z28mamaZl1

My 97 z28 has me stumped. I have replaced both O2 sensors, tps, maf, optispark, temperature sensors, plugs, wires, fuel pump, fuel filter...I'm at a loss. Most of the time my car runs great. But sometimes it seems to want to fall on its face on take off. And it'll also run a bit rough when it does. Codes don't show a misfire since I replaced the opti. But it shows it's running rich on both banks. Please, any ideas would be greatly appreciated!

Z28mamaZl1

The worst hesitation seems to happen between 1800-2200 rpms

WebKruzer

Check for vacuum leaks around the intake and throttle body area, it doesn't take much of a leak to though the PCM a curve.