Flashing check engine light, codes P0301 and P0302

I'll be driving down the road and all of a sudden it feels like I've lost a lot of power in my car. The check engine light will flash, and It becomes very hard to accelerate, requiring me to push in the gas pedal way more than usual, and the RPMs jump up pretty high. Then around 15-30 seconds later is stops, I get my power back and everything is normal. Light stops flashing. I have gone to AutoZone to get my codes read, and two separate occasions, both times throwing p0301 and p0302. Each time I've been told something different was wrong. I ended up changing my coolant temperature sensor, and my fuel pump which has the filter inside of it I believe. All 4 spark plugs, and all 4 ignition coils. Issue seemed to go away for a day and now it's happening again. I don't know much about cars so I have a feeling this could be something obvious.