Hi. Thanks to any or all who contribute to these questions. 2004 Infiniti g35x sedan. Code: PO345. Camshaft Positioning Sensor Bank 2 Driver's side / angled sensor. After reading other posts on how to replace this sensor, I have just a couple of questions. What size allen wrench do I use to remove the 4 hex bolts on throttle body? Secondly, I am told that you also need to remove the throttle sensor, however, once you do this, it may require a "relearn." What does that actually mean and how is this done? Take it to a shop and wipe out the codes or reset ECU or drive your car around for a few days after you replace the sensor so it can readjust the ECU settings? Can anyone share any light on these questions? Please try to answer all. Thanks. I appreciate this forum's members and their help.

 

What size allen wrench do I use to remove the 4 hex bolts on throttle body?
Not sure, try a coupe of them out? They usually come in a set.

Secondly, I am told that you also need to remove the throttle sensor, however, once you do this, it may require a "relearn." What does that actually mean and how is this done?
If you don't touch the throttle plate and don't disconnect the connector, then you won't have to do the relearn. The procedure is designed to tell the engine computer what it looks like to have closed throttle condition so that the car can idle properly - this is needed because the throttle is electronically controlled. You can find the directions in the factory service manual section EC. If you need further guidance, I suggest you use the search function to find the directions on idle air volume learning and throttle position closed learning.

Take it to a shop and wipe out the codes or reset ECU or drive your car around for a few days after you replace the sensor so it can readjust the ECU settings?
Either way is probably fine.