With CONSULT-II

Start engine and warm it up to normal operating temperature.
Select "SELF-LEARNING CONT" in "WORK SUPPORT" mode with CONSULT-II.
Clear the self-learning control coefficient by touching "CLEAR".
Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0172 or P0175 detected?

Is it difficult to start engine?

Fig 1: Scan Tool Display - Work Support
Courtesy of NISSAN MOTOR CO., U.S.A.