hey... got a 96 4wd. after i hit 10mph, it doesnt matter how much i push the gas pedal down, it just bogs.... its not hesitating, sputtering, or shifting wrong just the loss of power. theres also a new hissing sound...
only codes are for a couple of fuel solenoids but i replaced those and still nothing.... removed the o2 sensors and replaced but no luck.... bout to take it to a shop but wanted to give you guys a try before hand...

 

Not alot to work with but try to locate the hissing. New after the power loss or you just noticed it?