unknown problem

[Dali]

i jumped the computer and got the code. from the description it said sensor output not changed 50 sec. after engine exceeds 1500 rpm. then list possible problems, fuel pressure, injection fuel leakage, ignition system, air leakage or ecu. now i know its not ignition because i replaced all with new last summer before parking it, ecu is good, no fuel leak that i can find, only thing is a slight psst sound just as i rev the motor but only for half a sec. it sounds like it is coming from the middle of the engine between the valve cover and intake manifold. any help would be appreciated anyway thanks.

[pelado]

..and the code you got was.....?????