Hello All

I have not been on the forum for some time so apologies for making an appearance when I have a question but hopefully I can be forgiven and someone will be kind enough to help me!!!
I have had issues with my 07 plate veccy 1.8vvti missing when driving first time in the day. It has done 39k miles so I have just had the plugs replaced today to keep all the servicing in line with the recomendations to keep warranty valid. Whilst it was there they plugged it in and got an error code PO170 Fuel Correction Bank 1 Malfunction. They did not reset it or anything as said should take to main stealer as may be a lamba sensor or something similar which will be covered on warranty. Before I take it in I just wondered if anyone could confirm that this code is a Lamba sensor fault and if so will it be covered on my warranty?
Thanks in advance