Replace right side fuel filter and sender or both left pump and sender?
 

Hi, I have a 2004 525i that has a hiccup or stutter going up a long hill at about 75. (That's when it's most noticeable.) All the signals point to the fuel filter or pump needing to be addressed.


Does it make sense to replace just the right-side filter/sender as a reasonable diagnostic first step? Or do I have to replace both at the same time?


Will fuel delivery call a system fault? I had a precat O2 fault and I replaced both, but the issue seems to still be present.


The car has 85,000 miles on it. Appreciate your thoughts!