With CONSULT-II

Start engine and warm it up to normal operating temperature.
Select "SELF-LEARNING CONT" in "WORK SUPPORT" mode with CONSULT-II.

Fig 1: Scan Tool Display - Work Support
Courtesy of NISSAN MOTOR CO., U.S.A.
Clear the self-learning control coefficient by touching "CLEAR".
Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0174 or P0172, P0175 detected?

Is it difficult to start engine?