I've just come back from the AE. They ran another scan, same fault code as yesterday being (p2195) oxygen (a/f) sensor signal stuck rich - bank 1 sensor 1. On the graph itit shows sensor one flat lining but sensor 2 seems to be working fine. They have also checked the battery sensor switch and couldn't find an issue with that. Looks like I will definitely have to replace the front sensor in order to stop the warning lights appearing on the dash. They have cleared the codes again but it won't be long till they appear again (usually within 15kms of driving).