pops,stutters, no code thrown

1999 5.2 Dodge Ram update----------pops,stutters,and thwen regains power for a bit. No code thrown!,,,,,,,,,,,,,,,,,,,,,,,,,,,,This engine had multiple cylinder misfire . the dealer had a hard time finding it and guessed that possibly the o2 sensor could be sticking. they replaced the o2 sensor and that is what caused the probl;em. It took them 3 days to figure this out. I wanted to pass this on in case someone else has this problem with their truck.