I have just installed the K&N FIPK kit in my MY2005. At optimum operating temperature the idle will fluctuate from 1000 RPMs down to about 900 RPMs (one-notch below 1000 RPMs), then back to 1000 RPMs again occuring about every five seconds. I will mostly notice this sitting at a traffic light after driving the car for at least a couple of minutes. Is the idle fluctuation normal? I do not remember the car doing this with the OEM induction system, although it could have been doing it all along. Also could it be a small vacuum leak?

Thank you in advance for your help.

 

check your vaccum line

reset the ecm

 

i wouldnt freak out if its just one notch(900-1000), i've notice my S doing this at idle, it will fluctuate every 5-10 seconds or so.

 

are the air pump lines right?

 

Check to verify that all your lines where run correctly the reset the ECU by unplugging the battery for a few min. Then drive it for a few days while it relearns how your car is reacting. But if it still does it, then I wouldnt worry too much. Mine fluctuates whenever I roll the windows up or down, use the top switch, turn on or off headlights and when the fans kick on or off. So it may be normal!

 

dont worry about 100 rpms worth.. when i turn my headlights on it changes the idle due to more drain on the alternator

 

Thank you for the replys. The vacuum lines are all ran correctly and are tight. I think it is normal