P0300, P0302, P0304, P0306, Engine running rough with little power

[X5Cat]

So, you recommend the Veepeak VP201? What do I need the Hi Gain WiFi adapter for? Does it plug into the iPhone? Is it just to extend the WiFi range? Can I just sit in the car with the iPhone instead and be close enough without the Hi Gain adapter? Just wondering what I'm buying, I will buy whatever I need to. Also wonder if I could just go down to Best Buy and buy any Hi Gain WiFi adapter they have on the shelf. I see extension and splitter cables for sale on the site too, wondering what I would need those for, if at all.