my 2000 SLE Surges and misses at certain rpms while driving & will die sometimes at stop lights; not always ! check fuel pressure with key in on postion and jumps to 50 psi for about 2-5 seconds then down to around 44 and stays there ! is this normal ?? i changed coils/module- fuel rail-fuel filter-plugs wires-cleaned throttle body off engine! could it be a bad cat/conveter?? i have xtra parts from my 98 bonne 3800 motor, fuel pump is not the same as my 98.

The pressure is about right. Should be about 48-55 during the 2 seconds that the pump runs when the key is turned on. The spec that I show for how far it should drop is 5 psi, and you're just outside that. I don't think that'* enough to be causing your problems though. What'* the pressure with the engine running? Did you clean the IAC passage and valve really well while you were cleaning the throttle body? Is it at high rpms where you have your problem? Checked for vacuum leaks?

When you pressure test the system. You hook up the gauge, turn key on and depress the relief on the pressure gauge to remove any air. Do this a couple times..then key on a couple more times to gain the max pressure reading.

Almost sounds like you may not have released the air. (Guess how I know that one )