So... My 2007 Ram 1500 5.7 4X4 broke down on the freeway. There were 2 loud pops then the engine shut down. The check engine light came on and the truck would not start. My OBD2 reader was at home and there wasn't anything obvious I could see from a quick once over visual. The starter turned, but the engine would not fire. I was nowhere near home so I had my truck towed to a friends shop a few blocks from where I broke down. Their diagnosis was a bad fuel pump and I had them replace it. I do my own work and it just about killed me paying a shop to do this job. About 3 days after the repair, the truck threw P0440 and P0456 codes. I checked the EVAP hoses and connections. Everything looked fine. I cleared the codes.

Since then, I've run 4 tanks of fuel through the truck and have noticed 2 problems (in addition to reoccurring codes)
1- The fuel tank won't accept the full volume of fuel at the pump. It's 3 gallons short.
2- I'm getting about 5-6 fewer MPG.

I went back to the shop that replaced the pump and they performed a smoke test. It passed. They cleared the codes and suggested keeping an eye on it.

Any thoughts?
Thanks in advance
Pete