Another Update: The shop left the scanner in my car. My drive back to the shop... CEL turned on and idle fluctuation came back since i was there i told him if he could check it for me and it was nonetheless P0507: High idle I have not yet got a new PCV valve since he told me it wasn't working properly and told me to replace it and it should solve the idle issue but its odd because i changed the PCV maybe 4-5months ago and most of the time it was just sitting in the driveway, although it was an Ebay one so maybe it sucked or faulty. Now should i just buy a PCV from Autozone/O'reilly's or the dealership which i have no idea how to buy from a dealership (do i go in person?). He also showed me something that when i turn off the car a whistling of some sort not really whistle im not sure how to describe it but you were able to hear it when the car turned off and he showed me the sound went away when he took off the oil cap and the sound was located near the PCV area. im not sure wtf he was showing me tbh but he said it was related to that. Now what do you guys might think it is and Where do i buy this PCV valve thingy and is there a specific one i need to buy... I see some in O'reilly's ranging from $13-23 im not sure what the difference in them are so if someone can help me on that i would appreciate it. (07' 350z Base) EDIT: ALSO WANTED TO ADD THE CAR IDLES AROUND (1.2-1.3RPMS) AND WHEN I DRIVE IT IS WHEN THE IDLE EITHER STAYS AT 1.5K OR IT STARTS FLUCTUATING I ALSO HOPE THIS HIGH IDLE IS WHATS MAKING THE CAR HEAT UP A BIT ( THE TEMP GAUGE ON THE DASHBOARD SAYS ITS FINE BUT WHEN IM NEAR THE ENGINE IT IS HOT THAN WHEN IT USE TO BE.