Yesterday afternoon I changed my 1997 Subaru Impreza’s air filter. I didn’t turn on the engine after changing it, but the car was running just fine immediately beforehand.
A point (potentially) worth noting: while changing the air filter, I did clean out the inside of the air filter container with a wet cloth, as my car manual suggested.
This morning my car started and then died after 5-10 seconds. The engine “sighed” to a stop rather than abruptly dying. Every time I now start the car, this happens.
I’ve checked for loose hoses or wires around the air filter, just in case I knocked something awry, but I didn’t find anything amiss at first glance.
Did I cause this, or is the timing a coincidence? Any suggestions for what may be wrong and if I can fix it myself, or do I need to send it to the shop?
Thanks for your insight!
Obvious thing to check - did you leave the rag in there?
it does sound like a loose vacuum hose
You may have unplugged or disturbed the MAF sensor. Is you check engine light on the brief time that the engine does run?
I did this to myself ( slap forehead ) after having parts dis-assembled to replace alternator I headed down the street only to have NO ACCELERATION . The truck would roll forward in gear only at the idle speed with zero gas pedal input.
Pop the hood and…I didn’t put back the fresh air intake duct to the air filter ! The air flow sensor is on that duct, before the air filter, so the result was that the computer could not sense any more air flow than idle. Put the duct back on , slapped myself in the forehead, hoped no one was watching, and away I went.
The lesson here, re-check all the hook-ups even if you didn’t knowingly disconnect something, It might be off now.
Re-do the air filter, to make sure it is positioned and facing correctly and the fasteners are correctly fastened (I really don’t think that is the problem, but it is best to start over, to verify what was done). I agree that you may have knocked off a connector or hose; it is always good to go back and recheck the work that you did.
Thanks for these suggestions. I think I have found the culprit, after looking for loose tubes/wires. Here are some photos I just took to illustrate what I think is a disconnected tube – but before I go reconnecting it and potentially damaging the engine, I’d like some reaffirmation that this is indeed the problem… Thanks!
It sure looks like a loose hose to me. They should get together. ;o)
Put them together. It appears on our Subaru the set up is similar and there may be some play between the two. Ours doesn’t fit very tight. Try a restart; you won’t hurt anything by trying. If it doesn’t start, post back.
Sure looks like a disconnected vacuum hose.
Dude! This just saved my life. This is exactly what I did. I’ve been trying to figure this out for a week!
Thanks guys, almost lost my mind when my husband got home from work to tell me my suv was having trouble idling. The only thing I had done the day before was change the engine and cabin air filters. Come on Im a woman but I can change a a filter and bulbs. I checked and sure enough there was a plug that popped off. I apoligized for accusing him and fixed the plug. We alreay had one car down having both left me panicked. Love the internet
Just a note that I know several women who do their own engine swaps. No reason to think you’re any less capable of car work just 'cause you’re female. 
I knew a young woman who could remove and reinstall the engine in her air cooled VW Beetle in 30 minutes. She pointed this out as a primary reason her husband shouldn’t divorce her, as the “other woman” had no such skill 
Okay so yesterday I read this having done the same thing changed the air and cabin filteters and now mine wont idol when at a stop unless in neutral with foot on break. I reconected the sensor and it fixed it but check engine light still on it was fine for a bit this morning, then started up again. I have disconnected the battery to try to re set it. If that dosent work any ideas?
Resetting the light usually won’t fix physical problems that still exist. The light is just the messenger 
The next step is to get the codes read and that will give you an idea of what the computer is seeing. That will point you in the right direction for a fix. Once you have the codes, post back and someone here can advise what to check next…