I'd go ahead and spring for the one-day viewing subscription at
http://www.infiniti-techinfo.com. It's $20, and you can download your service manual and TSBs as .pdf files.
I had to replace the intake air temp. sensor on my truck due to broken wires. Easy to do - but there's also an ohm test you can use to check the sensor. With the service manual and a multi-meter, you'll be able to get to the cause of it without throwing parts at the car.
Speaking of parts - Joe at Infiniti of Scottsdale -
http://www.everythinginfiniti.com or 1-888-216-5328 has been a great friend and sponsor of NICO, and sells parts at wholsale prices!
Welcome to NICO!
Heath