engine misfire cruising on the highway

Have you looked at the plugs and wires?Is i worse with the ac on?

hi thank you! I replace the fuel pressure sender, map sensor, all four O2 sensors, fuel pressure reading is 50psi, spark plugs changed 3000 miles ago, i put a computer on it and it said my barometric pressure voltage is 4.25 which i think its suppose to be reading .5 volts. So i'm very lost can you help me? oh yeah it idles with a little miss and when i first get on the fuel slowly it bucks and chokes misses bad. then when i kick it down to the next gear it runs fine. but when its in overdrive going up a hill it does the same thing until it kicks into the lower gear. Any help would be appreciated.

can anyone help please only vehicle i have to get to work and pick up the kids from school

When is the baro sensor reading 4.25 volts at idle or with the key on engine off?

At idle or on the throttle

Do you have any codes in the computer?

No not at all....im lost....

So it never changes from 4.25 volts?

No not at all...so it's at max all the time thinking it needs max fuel...

What size engine do you have?

5.3

Here's the crazy part i dont see a baro sensor listed for it.I dont see any trouble codes listed for it ethier.I looked up component locations didnt list on for it.What is the map reading at idle?

I don't either...some one said it was run by the map sensor...but I put in a new map...and did not change anything...

What does the map.sensor read at idle?

I will have to check again lol

Let me know

1.25 v

1.25

Thats about what it should be.How are the spark plug wires?