i thought it was from bad gas when it started but it wasnt. under normal light driving conditions, she is fine, pulls hard. under load, she lags, bogs, and eventually pings. i checked injectors, cam sensor, crank sensor, all vacuum hoses, coil pack, module, fuel pump and filter. im not losing fuel pressure under load. set at 42lbs. i do have a crack in my drivers side exhaust manifold, could that be reaking so much havoc? any ideas would be appreciated, im all out of them. does anyone have a header of stock manifold? will send cash, please help.