Range Rover County LWB (LH) V8-4.2L (1993)
Code 31 - 40: Testing and Inspection
Code 40
NOTE: If code 29 is present, all other fault codes stored are unreliable and must be ignored.
Multi-meter Code Diagnosis
Code 40 - Indicates a left bank misfire.
Code 50 - Indicates a right bank misfire.