Good afternoon all started car up from cold this morning everything was fine went to shops , when I came back and started it this time the idle sat above 2000 rpm then started raising and falling

Drove it home and did a pedal test - I started it again but this time was just over 1000 rpm so tried again this time back up to 2000 rpm plus

Have a video to show happenings was not sure how to post it

Been told that 13008 is lambda sensor bank one sensor 1 but search engines say sensor 2 it had a new front sensor 3 months ago when a new front pipe was fitted - I do think that my front turbo elbow is leaking would this cause the sensor to operate in correctly

Cheers again

Andy