I noticed yesterday the pitch of the exhaust / engine noise has suddenly become deeper, not quite agricultural but definitely different to normal. It drives ok It revs ok It appears to be working normally It feels like it has a little less power but I can't be certain It is not as high pitched in low gear as normal Feels like it's popping and banging less on the overrun I cannot visually "see" anything obviously out of place Exhaust looks ok but that's only a visual inspection However it does sound different to me and " not quite right" but it probably would not be noticeable to others .... So any thoughts ? should I stop driving it immediately ? and take it to a dealer ? It is a r400d with TB's ....... Thanks all ! Andy