Hi guys Ive said hi now straight in with the questions!!! Just tried to MOT my lupo, had a couple of issues that I didn’t worry about but it failed badly on emissions. No problem I thought, put the cat back on and im through, but just had the retest and its still a million miles out. The tester said its over fuelling badly and suggested I try a new lambda sensor. Generally car runs well, pulls hard through the rev range starts first time hot or cold and theres not a hint of smoke from the exhaust. Im gonna try and vagcom it before I start spending but does anyone have an idea of where the problem may be? Spec is lupo sport 1.4 16v, 4 branch manifold, BMC filter. Thanks