Thanks - disconnected battery - light off. Stopped for 30 minutes in town, restarted light on - that's when I took it back. It runs ok ish at the mo. I went back this am and got my EML bulb and holder back - I'll fit it this weekend. Monday am it is into Ford garage for diagnostic check - £60 + VAT including 1 hours labour - hopefully they can give me a full report - they've quoted £140 ish for each sensor - I've seen NGK one's on Ebay - are they any good....