I've got a 2007 350 with dual Injen short ram intakes and motordyne cat back.
So I've been throwing P2A00 and sometimes P2A03 after resetting the check engine for awhile now. I first replaced the bank 1 sensor 1 with a bosche o2 sensor and still kept throwing P2A00. I finally took it to Nissan and they called me today to tell me that the O2 sensors are working fine but based off the data they were getting there has to be a leak upstream of the precat O2 sensors. They havent been able to pin point where it may be but I'm on here to see if anyone has some insight to where the leak may be?

I've got almost 90k miles on the car, could it be something that has degraded over time to cause the leak given the age of the car or maybe something with the Injen intake?
Thanks in advance

 

triple check all intake and exhaust connections.... check exhaust gaskets

 

Would the exhaust have an affect on the pre-cat O2 sensor though? I think the leak is upstream from that sensor so the exhaust isnt playing a factor in this. More air is leaking in from somewhere and Im running rich

 

http://engine-codes.com/p2a00_nissan.html#ixzz3jswT8bTz

 

Did you ever figure out whether an air leak was tripping your codes for P2A00 and P2A03?