i've just got a b16a2 swap done into a 96 civic cx... the guy who did the swap for me did a obd2a to obd2b conversion and i found there's 2 wires he labeled evap not connected to the ecu. when my car is warmed up, it idled irratically and if i sit at a light for more than 30 secs the cel comes on. i took it to get the code and it's saying it;s the primary o2 sensor. anyone has this happen before? should i change the primary o2 sensor first?