The code 2198 is not a bad HO2S, this code is set when you have a Variable cam timing issue. The code is normally set when the cam phase is out of sink, in most cases the timing chain and or phaser have an internal concern. This is ofter followed up with engine noise. Are you having engine noise and a rough idle?
The cam phaser are the (shoes ) that keep the chain tight, when the wear out or go bad this allows the chain to slap and change cam timing (rough idle). Unless you are a seasoned professional I would not attempt this job.