98 Subaru Forrester Stalls with in 10 seconds of start up

Was ANY other service done?(air filter for instance) Is the check engine light on? Do you know the exact code number the mech got?

Carl

Tim..... This is just one of the reasons "JiffyBoob"/ "Pit-Stop" and some of the others are a BAD idea ..... Others have had wrong fluids installed, oil drain plugs stripped out, filters crossthreaded. A few have had the tranny drained and the engine overfilled! Batteries filled with TAP WATER, brake fluid contaminated and/or wrong type....

I suspect they broke a connector, unplugged something or?? while in/under there.

Good luck!

Do you mean the 'knock' sensor by any chance? A bad one of those can put your car in 'limp' mode... it still shouldn't stall out though.

The only sensor that really actually matters is the oxygen sensor (or a possibly a MAF, since you have a 98 Forester, and I think those were MAF) in your intake.

Ask the mechanic what the actual codes were (i.e. number, like P1234), and post them here.

snipped-for-privacy@gmail.com wrote:

Here's an update on the situation. The mechanic looked at everything that could have been screwed up during an oil change and didn't find anything that could be causing this problem. After talking to him further said that he really didn't think the NOX (knock?) sensor was the problem. The mechanic also said that he had managed to get it running but it was real rough and it backfired on him once. Based on that he suggested that a better place to start was with the plugs/wires. As I was planning on having it "winterized" anyway I told him to go ahead and give it a tune up as well. I'm hoping to hear back sometime today on whether or not that worked.

To answer a few questions:

1) I don't have the error codes, I'll see if I can find out what they are. The mechanic did say that it looks more like they are the result of the engine running rough and not the cause

2)The place that did the oil change did "check" the air filter. They told us that it was fine and didn't need to be replaced.

3) They probably said "knock" (as that makes more sense) and I heard "NOX". I'll make sure to get that clarified.

I'm still not convinced that there is a connector loose or not connected.

The codes could help us diagnose the problem... even if they are the effect and not the cause.

The wires/spark plugs would indeed cause the car to run rough, but it would not cause repeatedly sputter and die exactly 10 seconds after... you car would either not run, or run crappy all the time.

Sounds more like something ECU related... meaning that (and I'm not an expert on Subaru ECUs so I'm just giving you my idea on how it works) when you start the car, for 10 seconds or so the ECU will keep it in "startup" mode, then after 10 seconds it goes into another mode... and that's when it stalls. Since it's not very likely that the ECU itself went bad, I would agree that it's some kind of sensor, maybe the MAF.

Or... it may be something fuel related, for example it may be a bad fuel pump.

It's really hard to tell without knowing more information (namely the codes...)

Try also search> Here's an update on the situation. The mechanic looked at everything

WEll, its somewhat common on some soobs to fail to clip in the bottom section of the air filter box - though your mech likely would have spotted that.

maybe something just coincidently happened like the belt slipped time - that could possibly yield backfiring. Or some kind issue with an injector stuck open ore something?

weird

Carl

I vaguely remember that someone had mentioned this kind of symptoms when the air filter was replaced and airflow sensor (which is located somewhere in the vicinity of air filter box) was left disconnected. The symptoms seem typical for Mass Air Flow (MAF) Sensor Failure

Just wanted to let everyone know that the problem was resolved. They performed a full tune up and it is now starting and running fine. It looks like it was indeed a knock sensor that was causing the error code. The tech said a couple of the plugs were really fouled and the gas filter was very dirty. So it looks like nothing was caused by the oil change and that it was just a coincidence. Thank you to everyone who participated in this discussion.

Tim