Catalytic Converter ... needs to be checked and/or replaced.
Replace the oxygen sensors. This should eliminate the 'rotten egg' smell. If the engine has lost power, the converters may need replacing. Though there may well be an electrical problem, a partial collapse of an exhaust system component could restrict airflow enough to cause the engine to 'run rough'. The rough running is an electrical misfire in the engine. The egg smell is the catatytic converter disolving with raw fuel going into it. You will have to check plugs, leads, cap and rotor arm for wear or damage. Dont drive this vehicle because you will have to add the cat converter to your shopping list too. Hope this helps
The 2007 Kia Sportage runs on regular unleaded.
The 2005 Kia Sportage runs on regular unleaded.
The 2010 Kia Sportage runs on regular unleaded.
The 2001 Kia Sportage runs on regular unleaded.
The 2002 Kia Sportage runs on regular unleaded.
The 2006 Kia Sportage runs on regular unleaded.
The 2008 Kia Sportage runs on regular unleaded.
The 2014 Kia Sportage runs on regular unleaded.
The 2012 Kia Sportage runs on regular unleaded.
The 2011 Kia Sportage runs on regular unleaded.
The 2013 Kia Sportage runs on regular unleaded.