Lambda sensor

Hi guys
My 10AE 1999 MK2 1.8 failed the NCT on Emissions. Im told from the readings the most likely cause is the Lambda sensor. Where can i get one for the most reasonable price as ive been on holidays and only have a few days left to get this sorted before retest.
Best regards Hazel
My 10AE 1999 MK2 1.8 failed the NCT on Emissions. Im told from the readings the most likely cause is the Lambda sensor. Where can i get one for the most reasonable price as ive been on holidays and only have a few days left to get this sorted before retest.
Best regards Hazel