Weird idle during neutral

[grammates]

So recently on my 08’ speed I’ve been having some issues one of them being that my idle has been weird lately. Specifically like in the video if I’m driving and coming up to a stop I can throw it into neutral and it will hover over 1000 rpms and bounce around like I’m downshifting through the gears. Once I come to a stop it levels out. I also keep getting the check engine light for (too lean at idle)
08 speed
HPFP INTERNALS
AEM cold air intake
Rear motor mounts
Cobb
Stratified tune
Sorry if this isn’t the right format etc I’m a newer member!
Link to video (https://imgur.com/DnuFb6j)


Sent from my iPhone using Tapatalk

[Vansquish]

Originally Posted by grammates So recently on my 08’ speed I’ve been having some issues one of them being that my idle has been weird lately. Specifically like in the video if I’m driving and coming up to a stop I can throw it into neutral and it will hover over 1000 rpms and bounce around like I’m downshifting through the gears. Once I come to a stop it levels out. I also keep getting the check engine light for (too lean at idle) 08 speed HPFP INTERNALS AEM cold air intake Rear motor mounts Cobb Stratified tune Sorry if this isn’t the right format etc I’m a newer member! Link to video (https://imgur.com/DnuFb6j) Sent from my iPhone using Tapatalk

What you're describing sounds like a classic vacuum leak. You should check all of the couplers and clamps from your intake all the way to the turbo, and from the turbo to the intercooler, and from the intercooler to the throttle body. Make sure all the clamps are secure and that the hoses aren't pinched or cracked.

In addition, you should check all the vacuum hoses running to and from the EBCS, as well as the VTCS actuator to make sure that they're all connected properly and that there are no cracks in any of the hoses or their connections.