Hi, My K11 has just failed it's NCT (MOT) with a Lambda reading of 1.05 when 1.03 is the max allowed. The tester guy said he tried to get it lower, but no go, and the engine temp was 87 C. He thought it might be an air leak. He also said people think dipetane works, but it doesn't. I drove to the testing centre at fairly high revs, and she runs well, and idles fine. Any ideas?