Direct fuel injection in 2011 Maxima 3.5

[daveburch235]

Greetings. I have two questions about the direct fuel injection in the 2011 Maxima.

1. I see nothing in the Nissan Service and Maintenance Guide regarding scheduled fuel injection service. Does anyone do any kind of periodic FI service anyway?

2. My mechanic (not a dealer) is tyring to sell me a $300 intake valve cleaning, on the argument that the change from port fuel injection to direct FI means the carbon no longer gets cleaned off the valves by the spray of fuel. My research on this tells me it was a problem in some early adopters of DFI, mainly German makes, Cadillac, and Ford. I see no indication that any Nissan engine ever had this problem. Any opinions?

Thanks!