I have service engine soon light. Failed emission inspection and showed codes p1140 and p0420
You should start by fixing the P1140 code. Sometimes the code is caused by dirty engine oil.
P1140 INFINITI - Intake Valve Timing Control Performance Bank 1
Read more: http://engine-codes.com/p1140_infiniti.html
P0420 INFINITI - Catalyst System Efficiency Below Threshold Bank 1
Read more: http://engine-codes.com/p0420_infiniti.html