2001 S10 stuttering/loss of power

I recently purchased a 2001 S10 with 138K miles && am experiencing sputtering/bogging out when trying to accelerate (even lightly):

1) It rarely sputters on the way to wrrrk at 4a.m. - only on the way home in the super-hot afternoon, and then generally only after 30 minutes or so of driving.

2) Shutting the engine off and restarting it will make almost always make the problem temporarily disappear (for between 5 && 15 miles)

3) It has only lit the CEL once after I tried revving it up while it was misbehaving and it backfired some. AutoZone read/reset codes P0452 && P0300. Todays commute was the same fare - fine in the a.m., sputtery after about 20 minutes, no CEL

4) I removed the gas cap and it appears to have slightly improved the performance… that could just be a misperception of mine though.

5) It usually starts right up, no problem… but once in awhile it will require extended (2 to 5 minutes) cranking to start.

Any further insight would be GREATLY appreciated!

PO300 means: Random/multiple cylinder misfire detected.

PO452 means: Evaporative emission control system, pressure sensor low input.

I’m not a tech so I’ll let our resident techs answer your concerns.

OK, can you explain these codes to the poster? I don’t want to give the wrong info.