I have the same issue. I've had my 2010 1.8 for three years and I've gone through all the cheap fixes to address the rich running condition.
Pcv, o2 sensor, intake gasket, vacuum leak test.
My belief is there an exhaust leak upstream from the second 02 sensor. Either the bung attaching the manifold to the exhaust or the manifold it self. This would give the o2 sensor bad info for fuel ratios. I assume you get bad mileage, lower than normal power, rough inconsistent idle and an occasional back fire. Leak test your exhaust, that's my take.
