Cold air intake startup

[subaru13]

I just installed a cold air intake on my 2.5 legacy gt and it sounds amazing but after having it on there for a few days I have noticed that after the car has been sitting for awhile like 2 hours or more the car has problems starting up... like sometimes it will start up and run really rough and sputter and then after like a minute it will be fine and then sometimes it will startup up and just die. Has anyone else had this problem??? And if so what did you do about it and how did you fix it?

[2.5GT]

make sure you check all your vacuum lines. especially the big hose coming off the intake manifold.

[99SUS SFD]

Did you reset your ECU after the install?

[subaru13]

Yeah I have the big vacuum line connected, but I have it going into a smaller hose which I think may be the problem but I am not sure, and I also did reset the ECU...at least I think. Correct me if I am wrong but all you have to do to reset the ECU is to unplug the power to the battery for at bit and then reconnect it...right?

[99SUS SFD]

Yeah it takes a little while if you just let it sit. What you can do is disconnect the negative for a few minutes then press down on your brake pedal to get rid of the stored energy in the system.

[subaru13]

How long should I leave the negative disconnected?

[HeresMyMind]

i leave mine over night. and it completely wipes everything. any stored codes or yada yada.

-B

[subaru13]

so if I leave if unhooked over night it should theoretically fix the problem?

[99SUS SFD]

Not necessarily but possibly. It'll help the ECU learn that it's getting more air and may help the engine out.

[dplacencia]

The problem is the big hose going into the small intake hose. I have the same problem.

[subaru13]

You know I had a feeling that the small hose to big hose was the problem.... Well Does your car still do the rough start up or have you fixed it?

[subaru13]

Alright so I left the battery unplugged over night to reset the ECU and when I went out there this morning I went to start it up and the problem was even worse then before....It now dies two or three times where as before it was only ever dieing once. So I decided to drill a bigger whole in the piping for the big vacuum line so I didn't have that big to little hose situation anymore and it seems to start up fine now..but the real test will be the startup tomorrow morning after the car has sat over night.