Currencies of a number of emerging Asian economies remain undervalued, substantially in the case of the renminbi,” the IMF said in the report. Renminbi is a name for China’s currency, a denomination of which is the yuan. It’s essential for China to address excess demand pressures by reining in credit growth and allowing exchange-rate appreciation - IMF
Additionally the IMF said debt laden countries should let their currencies depreciate:
In advanced economies, fiscal consolidation is needed but is likely to have an adverse effect on demand and growth. To offset these adverse effects and maintain growth, advanced economies as a whole may need to depreciate their currencies so as to increase their net exports - IMF
i.e. the world is out of balance and the China Yuan currency peg is a major reason why.