I was driving & all of a sudden no power. While in park it idled fine, can rev the motor, but put it in drive & put the pedal all the way down & you might hit 25-30 mph. I have so far changed the fuel pump & filter, bought 8 new coil packs (code running lean & now no codes) changed the mass air flow sensor, throttle position sensor, air charge temperature sensor, & cut the catylac converter off with no change in the way it runs. Any thoughts?

 

The engine computer relies on info from sensors before and after the converters for fuel and emission control. Have they been confirmed as functioning properly?