Everyone seems to say that this is normal and "was designed" to work that way to quickly heat up the Cat. to "reduce exhaust emissions". Well this may be so, however, why is this oddity required when all other car manufacturers who also have Cats in their cars didn't have this "brilliant" invention and why wasn't it a "copy cat" item if it was such a brainwave from those designers??? Lets face it, even the latest new Mercs have got rid of this problem haven't they? An after thought perhaps?