I noticed some problems with my truck and when i reset the pcm all the problems went away for the reset period. After restting and driving for about 50 miles the problems came back. My question if those problems are real problems, wouldn't they exist always? I am thinking my pcm is bad but not sure if a pcm while resetting can make problems dissapear until reset is finished.....help!

 

Most likely once the PCM relearns all the sensor data then it acts up. Most likely a sensor like the O2 or coolant temp sensor is bad.
What year is your truck so I can move this into the correct section?