93 Astro rough accelleration

I got a check engine light and I started noticing poor/rough accelleration with my astro van so I had a friend check the codes.

45 Oxygen Senser Rich Exhaust
54 Fuel Pump Relay or Circuit fault

I replaced the O2 Senser. No change. Then replaced the relay, still no change. The codes seem contradictory; if the relay isnt sending enough voltage to fuel the pump than wouldnt the mixture be lean?

Does anyone have any suggestions as to whats going on?

Thanks

Do you have a W or a Z engine? Look at the 8th digit of the VIN.

tc 45 on mine was from a missfiring cylinder pumpin unburnt fuel thru and running real rough, check you ignition system. mine turned out to be the distributor but it could be anything in the ignition system