Just today I noticed a 750 rpm idle and stalled on my 2 mile ride home. I didnt do anything different today. Over the past few months I have noticed a little "sputtering" or hesitation when taking off from a red light. That started around the time I installed a Fram AirHog air filter. Anyway the main problem is the stalling. Its a 99 Legacy 2.2L 68k miles, no previous problems.

 

Please help!!

 

 

 

UPDATE: NO PROGRESS, tried checking tubes, all seem in tact. Filter is in securely and closed properly. The Fram AirHog is the same thing as a K&N Air filter. This should give it more air than it needs rather than less. Whats a normal idle? mine is still at 750.

 

UPDATE: CHECK ENGINE LIGHT ON-took car to my mechanic, he cleaned the throttel body. 30 miles later my check engine light came on. Idle is still low. After driving a straight 200 miles it stayed on. after 2 trips around town, a few miles later it shut off. came home from the trip 225 straight, check engine light still off. drove it later in the evening and the annoying light is on again. Mechanic on vacation, how canvenient. Wont be able to get the codes off till next week. Any ideas???? Please help!!!!!!!

Check all of the hoses coming off the Intake air ducts, you may have pulled some off.

 

Try a different filter.

Check all of the hoses coming off the Intake air ducts, you may have pulled some off.

 

Try a different filter.

I agree try a different filter, sounds like the air flow is restricted.

Are there any diagrams online where I could find all of the air hoses to check for bad connections?

Are there any diagrams online where I could find all of the air hoses to check for bad connections?

The one that gives the most problem is under the thing that connects the air filter housing with the big black plactic thing that sits on top of engine near back. It will be about 5/8 in. diam. their is also a small one that connects their. If the car will stay running the big one is most likely still on. I would try putting another filter in or make sure that one is in right, it sounds like you are not getting enough air to engine. Did you tighten the clamps back on the air filter housing?

I am also having the same problem. If I am sitting at a light sometimes the low idle causes it to stall. I have not changed the air filter recently. This only started the last few weeks. I have replaced idle control because the cel said it was malfunctioning. However that didn't help the problem. This is becoming a real nuisnace. I don't know what else to do. Any ideas?

I called my mechanic and have an appt for tomorrow. He said the subaru throttle get gunked up and causes the hesitation. I dount I will be lucky enough to fix this just by having him clean the throttle but I will post an update after he tries that. I found some more info when searching for hesitation, only suggestions to replace expensive parts though. None of which guarentee a fix. The manuals someone placed on this site said my engine (and most subarus) idle between 600-800 rpm. Maybe my idle isnt low but the 2 times it stalled arent good, and the hesitation is annoying.

If you had the 2.5L engine, I would bet on a carbon issue. I don't know if the 2.2 of that era suffers from the same (mild) ailment. I've not heard that it does.

 

When I had carbon build up, it was very much as you described. My idle was fine, but I was getting a slight delay, or hesitation just as I would take off from a stop. Getting on the throttle gently would cause that "pause". As it got worse, the engine rpm would even drop at times. I never stalled, but I came close once. If you dipped into the throttle more aggressively, the car acted just fine. The problem very slowly got worse. I could even feel what seemed like a slight 'miss' when going thru town with engine at about 1400 or 1500 rpm. Anyway, a MotorVac treatment cleaned out the carbon and resolved the issue.

 

The problem came back on me a few years later. I had an O2 sensor getting weak / slow (no codes yet, but the scope showed it acting slow) that was causing the car to run rich. The problem gradually went away after changing the sensor. If you've never changed your O2 sensor, you are at the age where it is due.

 

Commuter