obd codes for 2006 Mercedes Benz r350 p2187 and p2189, are up stream or down stream flows

Question

Check engine light on and scan read system too lean at idle bank 2 p2189 and system too lean at idle bank 1 p2187

Answer 1

P2187 , P2189 Lean condition , this is a vacuum leak, check at the PCV and the oil seperator these hoses tend to collapse and rot. The vacuum can also come from the oil cap not being secured. Listen for the vacuum leak with the engine at idle you may be able to find it