If you drive a 6mt and have the Injen CAI installed please do the following test for me. This requires driving 80mph so please do not procede if you do not feel comfortable driving at this speed.

Heres what I want you do do. Drive on a straight road at 80mph, then shift into neutral or hold down your clutch pedal. Wait for the Revs to drop to idle, and then please post your idle rpm's.

the reason why I am asking people to perform this test is this. I noticed that when I drive 80+mph and disengage the clutch, several things happen.
1. The rpms drop to about 1200, then drop instantly to 300, then bounce back up to around 1000, then as the car starts to decelerate, the rpm's start to smooth out at around 600-700 which is normal.
2. 3/5 tests I performed, the rpm's dropped so low, the engine stalled.

Now heres my theory of what's happening.
My theory is not that the engine is getting too much air, but the engine is not getting enough air. Heres my thinking:
-When you disengage the clutch, the throttle body is pretty much closed with a very small opening, it lets in just enough air to let the engine idle at around 600 rpm's.
-The location of the Injen filter allows the filter to get direct air flow entering from the front of the car. There is no obstructions to deflect the air.
-WHen you're driving 65+ mph, the air enters the front bumper and hits the filter directly, causing the bernoulli effect. When the velocity of air increases, the pressure decreases. So the pressure around the filter is very very low.
-So when you're driving above a certain speed, and let off the throttle when the car is in neutral, there just isn't enough vacuum inside the CAI to allow the engine to get enough air. If you go fast enough, air might even be sucked out of the intake.

I'm going to install an Injen heat sheild/deflector to try to obstruct the airflow and see if it helps. Also, it'll protect the filter from mud/dirt/etc... because the oncoming air doesn't hit the filter directly.
http://www.racerwheel.com/inj-hs5000p.html

Be careful trying this. If your engine does stall, just engage the clutch again and it should start back up. Just look at your engine speed and check for fluctuations in the RPM's. If it looks like your engine is struggling to idle, but it back into gear immediatly.
I already know that one other person as well as myself have this problem. If there are more of you out there with this problem, we need to contact Injen immediatly to stop selling this intakes because it could be very dangerous. I don't think this problem effects automatic owners because the torque converter never physically disconnects the engine from the transmission.

I already know that one other person as well as myself have this problem. If there are more of you out there with this problem, we need to contact Injen immediatly to stop selling this intakes because it could be very dangerous. I don't think this problem effects automatic owners because the torque converter never physically disconnects the engine from the transmission.

I drove more 80mph but nothing happened.....
Must be the driver, ;o) LOL

G-UNIT

um....I saw the similar problem twice while I was driving at 60km/h in my completely stock 5AT coupe too. What happened to me is, when I released the gas pedal, the rev just dropped below 500rpm, and I can really feel the car is going to stall. Then the car changed gear(or pump gas...I am an inexperience driver) and the car back to around 1000rpm and everything become normal.....

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Ivory Pearl G35 Coupe 5AT + Performance Pkg

In case ya'll haven't seen it yet, Phillip from Injen wants you to post your problems with the CAI in this forum so he has one place to track the problems from and can help resolve the issue quickly.

Here's the forum: Injen Technology - Infiniti G35

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

I posted this thread long before Phillip posted his. I was the one that contacted Injen about this problem in the first place.

I realize that, I just thought that any newly posted observations of the problem would be more constructive in the thread where someone from Injen is more likely to be reviewing them. I hear they think they have a fix, though.

2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter