A week or two ago my truck started missing/hesitating on me. I replaced the o2 sensors because the only codes it threw were for those. I've drove it approx 100 miles since then, and no codes have came up. Sometimes it runs great and sometimes it misses and carries on. I put a new fuel filter on it earlier today, and still no luck. If anyone could help, I'd really appreciate it, it is driving me crazy slowly but surely!
Details: 97 F-150 4.6L, auto, 4x4, it's had straight pipes on it for a while and they never have hurt it before

 

Did it have p0171 and p0174

 

Nope