Interesting! I would not think there would be any kind of link between a P0300 and your idle speed... but who knows (probably Nissan).

As far as the fuel cap replacement goes... I wouldn't think the two would be related (but again, who knows...) ... which makes me think the code may have been completely different the previous times. Or also possible is the light went off coincidentally with the gas cap replacement. Since the code wasn't pulled those times there really is no way to know... I would probably just forget that earlier "data" because there was a lot of guesswork involved.

Have you pulled or cleaned the throttle bodies recently or anything like that? If so did you forget to perform the throttle body reset procedure?

You may want to perform that procedure and the idle air relearn procedure just to see if it corrects your idle.

Also, did you clear the P0300? Maybe the idle will normalize after the code is cleared? Just throwing out ideas now.

For the OBDII reader, I have used this one in the past and it worked perfectly for reading/clearing codes (way too slow for real time data though):
https://www.amazon.com/Veepeak-Bluet...bdii+bluetooth

I don't believe it is iPhone compatible though..so if you are an apple guy you may have to track something else down. Worked great with my android phones.

As far as the filters go - K&N Website cautions against over-cleaning/oiling and shows a picture of what they should look like (absolutely FILTHY) before they need to be cleaned. At 50k, I would think you should definitely check them!!! Pulling the bumper is no big deal... I have done it enough times that I can do it in about 5 minutes not without even lifting the front of the car.

I would hold off on doing any kinds of upgrades until you have a handle on what (if any) problems your car is having.

The idle gets raised to 1k rpm when that code pops. Clearing it will drop the idle back to where it normally is. P0300 is a real pain in the *** since the ecu uses it as a general catch all code when something weird happens. It very well could have been caused by the fuel cap before, and by something else this time. Clean tbs and mafs, and see what happens.

As usual Chuck has all the answers. =)

Clear the code... see if it comes back...

Cant I just take the tube off and lift them out. Rather not take the bumper off. As for dry or oiled I dont know. I am not the original owner of the car

You have to take the bumper off. It takes fifteen minutes.

And only that long the first time you do it. Taking off the bumper is far, far easier than trying to fish the pipes out from the top and then trying to get them back in (which probably isn't even possible with the filters on).

If you ever plan on doing any work on the car yourself, learning to pull the bumper is a good thing anyway =) It really is much easier than you think.

This is why I love this place... Sadly I am about as mechanically includes as a two left handed giraffe. I will attempt the bumper this weekend. The other stuff you all said... was like greek to me... ugh

Yeah we all start somewhere but trying new things out on your own is how you learn! Here’s a diy on the front bumper removal. You will be able to do it! http://www.the370z.com/diy-section-d...r-removal.html