So for the past while my 2003 feels like it's low on power/ engine cutting out/ engine stuttering. When I put a fuel pressure gauge on it for about three days I had it on it never stuttered or cut out so the fuel pressure was constant. The fuel psi was around 48-50 psi. I can't figure this out. I want to say it's the fuel pump but I don't know.

 

Does it have any trouble codes?

 

None, this also does not help me.

 

I had a fuel pump go bad in an old minivan I had and it never gave me any codes either. That seems to be common on many vehicles. Also, crank position sensors often give no codes when they start to act up. Sometimes they go completely dead and never give a code.
With your fuel pressure readings looking good, the CPS might be a good direction to look. When the CPS signal stops, the computer thinks the engine is not running, basically. It will shut down the fuel pump, ignition and injector pulse.

 

Check the hard plastic vacuum line coming out of the right hand side of intake manifold, trace it back making sure there aren't any breaks, Check to make sure your intake bolts are tight and lastly I would attempt to clean MAF sensor.

 

These are all good things to check too. Much better to check and/or clean things than to throw a bunch of parts at it.