How about the rubber hose that goes from the Drivers side valve cover, up to the CAI. If that is loose or leaking, it could cause some idle problems. Check that connection. It should be on the underside of the CAI, close to the Throttle body.

 

That was the hose the came loose that caused my idle problems...

 

INJEN installed my CAI and it runs fine

 

Had about 4K miles on my Injen CAI with similar problem. RPM's would drop for a few seconds before recovering. My fix was done yesterday. Reinstalled the OEM with one exception. Used the Injen polished tube. Had to drill 3/4" hole and J B Weld fitting for vacuum line. Also had to cut 3/4" to 1" off the end of the tube attached to the OEM Air Sensor. Using the Injen Tube gives it a clean look. If this had been done without me knowing, I don't think I would have notice Injen CAI missing, with exception of "no" RPM drop.

 

Should be getting my Injen CAI monday, probably put it in tuesday. I'll make sure to avoid all the install issues mentioned above, and we'll see how things turn out.

 

My install is perfect, I'v double checked at least three times. Going to the short ram has eliminated the worst of the bad idle, But, I still notice a little roughness.

I think I'll put the stock on and have the dealer check it out.

 

As I said in a previous post, the OEM was reinstalled using Injen polished tube. Looks "Great" and the RPM problem is gone! The K&N filter for the OEM box should arrive by mid week.

 

not sure this is going to help much, but i put a short ram intake on my sisters car and it also idled rough. considering her car is a POS, i just left it on there. eventually, it idled like stock after 500 miles.

all this talk about aftermarket intakes makes me want to stick with the stock setup

 

I was reading up on the changes Technos makes to the Z ECU. They claim that the stock programming can overcompensate for some intake mods and result in a loss in hp. just a thought.

 

I had the same problem and this worked for me:

Idle Air Volume Learning Procedure

Perform each section or just scroll down to this one. The car must be fully warmed up, drive at least 20-minutes.

 

This problem occurs too with the AEM CIA. I have the AEM and it seems to idle rough. It tends to idle low. My idle is right after the 3rd line on the rpm gauge but before the 4th line(starting from 0). It stays like in the middle of those two and drops very little and goes back up. Like if it wants to shut off. Is this how everyones idle is or is it higher. Also if i disconnect my battery and reconnect it after, will i need to reprogram the ECU following the techno square process?

 

So, did anyone ever find out what the problem is? My Injen caused the rough idle in both CAI and S-Ram configurations. I reinstalled the stock intake and the idle problem got a little better but it still wasn't perfect. I took it to the dealer but they told me that the ECU didn't have any error codes and that they didn't witness the problem. With the heater on the idle problem is almost non-existent so that's how I'm assuming the tech test drove it. Assuming that the problem was just a bad tank of gas, since it didn't produce any error codes, I recently reinstalled my Injen S-Ram and the crawford plenum. The problem is A LOT worse now and it feels like the car is about to cut off and the lights even dim a little. I did the Idle Air Volume Learning procedure located in the service manual and on TS's website but that didn't help. Any ideas what the problem could be? All of the hoses and clamps are tight. I'm thinking that the idle might need to be raised a little but it also feels like it's misfiring as well. I'm wondering if my car is running too lean while at idle.