Okay, so I was driving down the highway and all of a sudden the engine started to stumble and backfiring. I pulled over and after a few minutes it fixed it self. Just this weekend, it did the same thing. I checked the fuel pressure and it reads 52psi, 60psi with the vacuum hose unplugged from the fuel regulator. I kept the gauge on to see if it dropped psi, but it held. I checked the MAF sensor to see if it was dirty, and it's clean, also checked the throttle body and it was nice and clean. I checked for vacuum leaks using a vacuum gauge and spraying throttle cleaner around intake manifold and it was fine. As I was checking it... it started to stumble and it would fix it self. The passenger side smells like raw gas when it stumbles. Check injectors connectors with a noid light, and also checked for spark on each coil and it is fine. I am also not displaying any codes. What am I missing, O2s?