Idles too high

As of yesterday I'm the proud owner of a 95 mx6 2.5 v6. Unfortunately its not running too well at the moment. When I started it today the idle remained high, the surged up and down for a bit before settling down. The idle now seems to be staying around 1200 rpm's when warmed up. After idling for a while it actualy setled down to round 600 rpm but for the most part stays around 1200. The check engine light comes on and then goes off. I pulled 2 codes 24 o2 sensor and 41 vris solenoid. Would the bad o2 sensor cause the high idle? How hard is it to replace the o2 sensor towards the rear of the engine? Do I need to worry about the vris solenoid or can that wait for a while? Money is a bit tight at the moment.

o2 sensor could make it idle rough as it is what controls your fuel air ratio.