Ok so the fact that you unplug the sensor and the problem goes away means that the actual issue is coming from the o2 sensor IMO.

The o2 sensor in the VX should be a 5 wire OEM wideband sensor. This is what controls the lean burn functions which saves you gas.

Bosch is probably crap. 2 wires is definitely wrong. For a brand new Honda 5 wire o2 sensor, expect to pay around $300. Welcome to the world of 45+mpgs. Normal o2 sensors for that year of Civic would be 4 wire. I have no idea where you got a 2 wire from.

IF the problem was fuel or EGR or anything else, the problem would persist, or even get worse when there is a CEL on for the o2 sensor being unpligged, the problem would not resolve itself. Let me know if you have any other questions.