i've got a 99 m6 z28. it has kooks lts, kooks ory pipe, borla catback, ls6 intake, whisper lid, and a bo white ported tb. yesterday i noticed that the fuel pump in the rear was making a louder noise (the noise that it makes when it is running was louder than normal). well today i got on it and after 2500rpms it started cutting out. what could this be? the only thing i've done different this week was getting gas at a gas station in another city. i know the gas could cause the cutting out if it was bad. why is the fuel pump working louder? i mean you can hear it plan as day inside the car with it running. any help would be appreciated. oh it is throwing a p0153 code, but has been ever since the header install.

 

Maybe a fuel pressure gague at the rail will show if the pump is good our not.