Ok so 99 civic dx hatchback swapped a B16a2 into it. Got a intake manifold, intake, headers and a catback exhaust. so here is the question at what point should I start think about exchanging and upgrading my fuel injectors, fuel rail, fuel regulators, throttle position sensor, map sensor, o2 sensor, ecu and whatever I need. This is my first swap and I have been looking around on how to do this swap and a majority has came from trial and error. So now the engine is in with the upraded bolt ons but now I want more power and I been reading that some are replacing these items. But where do i go to find these parts and at what point do I really need to?