So I have a new MAF coming in since I think mine is on the brink (supposed common issue with a P0175 code). I'm also going to be putting in a custom BBMAF. Knowing that a new MAF on 00-01 maximas require an ECU reflash, would you guys recommend doing the reflash with the new MAF/Stock housing? Or get the reflash done with the new MAF sensor in the BBMAF housing?

Thanks,

 

The car will run fine without the ECU "reflash".

The reason Nissan recommends reflashing the ECU with a new MAF sensor (22680-2Y001 Sensor) is because, according to Dave Brunette (parts guy from South Point Nissan) it makes the car run slightly richer in open loop and the dealer flashes the ECU to correct for this.

Since you are running the e-Manage Ultimate you can make any changes in AFR as needed, and you will not have an issue.