Check Engine Light

Quick question regarding what step to take next. I have a 1998 F150 4.6L V8. For the last month it has had 2 check engine codes for system bank 1 and 2 being too lean. I have the replaced the MAF sensor, fuel filter, and vacuum fuel separator hose. I took it in to get looked at and was told the fuel pump was the issue. Now after replacing the fuel pump both of these engine codes are now back. What should I check/do next?