flaco ev

I'm the proud owner of a 2001 Chevy Venture WB! Its a great van! Drove my family and I from Germany to Denmark for X-mas one year with no issues! Yet now, for awhile, I received a P0341 code! Also P0300 code, misfires on cylinder #3! Van started running really rough! I bought myself a new Cam sensor, and coil, installed it, cleared the code! Nothing changed! Left the van sitting for a few weeks, started it up, check engine light went off! Hoorah! Couple days later, van started running rough, especially on a load, check engine light pops back on! Guess what... P0341 code! Should I go ahead and replace Crank Sensors, and Cam sensor and be done with it? Is there something I'm missing that someone could enlighten me on? Thanks