Have a 5.7 with auto. When I hold the brake and give it power it runs great. If I go down the road and hit the accelarator it dogs down and barly runs. I have changed the MAP, Downward OXY sensor, checked fuel preasure. ANy Ideas??
Thanks

 

Hey,
I had a very similar problem. Anything in over drive or if i would just step on it in higher gears, down low it was fine but higher gears like yours.

Sorry to say but my tranny was pooched....That was my problem atleast. Hope you have better luck then me.