[eandsphotography]

Hi. I have a 2001 outback LL bean with the 6 cyl. Went on a quick weekend camping trip the other day and ran into a little bit of a problem. I tow a small A-liner trailer with the car (1300 pounds) and it does a great job.
Left home and drove about 150 miles and right before I got to my destination, I fiiled up at a shell station (always use premium grade) and as soon as I got back in the car, it started Idling really bad for a minute or two. revved it up a bit and it seemed to smooth out. Drive about another 30 miles without any incident and then right before I got to the campground the Check engine light came on a couple times and was flashing, but then once again it seemed to smooth out and was running ok again. Didnt have any other issue with it the rest of the day.
Left the campground yesterday morning and made it almost all the way back to my house again (150 miles) and I had to stop and put gas in. I only put in a couple of gallons just to get it back home cause I like to fill up at a station near my house that sells pure gas and not the ethanol blended BS.
So put a couple of gallons in and about 2 miles from my house, the car started running horrible. Rough idle, sounds like a cylinder is missing, feels like it wants to die ( did not stall though). CEL light came on and flashed a few times and now it's staying on completely.
Popped the hood when i got it back in the garage and checked the oil level, checked for any oil leaks, etc. But when the car is idling low, the engine has a definite vibration, shudder, to it which it never had before.
So, with all of that said, I was wondering what are some pre-diagnoses before I bring it in to see what the codes register?
I should note, that the car seems to be shifting fine so it doesnt seem like a tranny problem. I'm thinking something to do with the fuel pump, filter, injector, etc.
What are you guys thoughts on it??

 

[idosubaru]

That's a cylinder misfire the code will be a cylinder misfire code for the check engine light.

Most auto parts stores will read the code for free - Advance Auto Parts, Autozone, and more. No point in paying a mechanic and making arrangements to drop it off when you can do it on your own time for free.

How many miles?
Have the spark plugs ever been replaced?
At 10+ years old they may need it.

It is likely:
1. spark plugs
2. coil pack(s)

The mechanic can swap the coil packs and see if the cylinder misfire code "moves" - in other words if you move the coil pack from cylinder 2 to cylinder 4 and then the check engine light code also moves from cylinder 2 misfire to cylinder 4 misfire - then you know it's the coil pack.

 

[eandsphotography]

the car has just about 110,000 miles on it. I also figured it was do for a plug and wire change but i was putting it off as long as possible because I just dont know if it had done before I bought it at 95,000 miles. It was well maintained from the owner who traded it in at the dealer where he bought it from and then where I bought it but they didnt have any records of ever doing a plug change. Doesnt necessarily mean it wasnt done, just not at the dealer.
I'm not very mechanical , so when you say the coil pack, is that a high dollar part to change??
thanks.

 

[Greghhh]

Off hand, it sounds like a missing injector. The fuel quality could be in question of the fuel filter is plugging up causing low fuel pressure. Checking the code will give a good place to start at least.

 

[cardoc]

Hi,

Get the DTC. Post them. We can go from there. No sense wasting your time speculating and getting worried over it. It could be any number of things. You could have pumped bad gas in and the computer can't compensate at low rpm or something went awry by coincidence.

 

[CNY_Dave]

My car acted just like that when the throttle-position-sensor crapped out. The number of things that can make the car act like that is such that you really need to pull the codes.

Autozone and advance autoparts and pep-boys will pull 'em for free.

 

[idosubaru]

the car has just about 110,000 miles on it. I also figured it was do for a plug and wire change but i was putting it off as long as possible because I just dont know if it had done before I bought it at 95,000 miles. It was well maintained from the owner who traded it in at the dealer where he bought it from and then where I bought it but they didnt have any records of ever doing a plug change. Doesnt necessarily mean it wasnt done, just not at the dealer.
I'm not very mechanical , so when you say the coil pack, is that a high dollar part to change??
thanks.

get the codes read and post them here. as i already mentioned, places do it for free. do not tell us what the guy tells you about the code, give us the exact number read by the scanner.

 

[Scooba Steve]

the car has just about 110,000 miles on it. I also figured it was do for a plug and wire change but i was putting it off as long as possible because I just dont know if it had done before I bought it at 95,000 miles. It was well maintained from the owner who traded it in at the dealer where he bought it from and then where I bought it but they didnt have any records of ever doing a plug change. Doesnt necessarily mean it wasnt done, just not at the dealer.
I'm not very mechanical , so when you say the coil pack, is that a high dollar part to change??
thanks.

Get those codes pulled! :whip:
regardless to the problem that awaits you, get those plugs and wires done.
i like to use not knowing what the previous owner did as an excuse to buy more tools and tinker around with simple tune up procedures such as plugs, filters, (air,and fuel) and fluids.
one of my favorite quotes would be:
most "previous owners" in one way or another are selling you there problems.

 

[plain OM]

I'm hoping some code other than a simple "misfire" will be reported.

I've been a strong supporter of "getting the codes" because some of them are reasonably specific -- they identify a circuit or function that has a distinct flaw (e.g. an open circuit to a solenoid). However, other codes only say that something is happening, but provide little if any guidance to the cause; these include the P0420, and the P030x codes for misfires. In the latter case, all it does is confirm (if that) that the physical symptom being experienced is caused by a "misfire", but not what's causing the misfire. (There's no DTC for common causes of a misfire, such as a fouled plug, arcing plug wire or coil, clogged injector, failing fuel pump, or even bad gas.)

Once a P030x-type code is reported here (which I fully expect in this case), it seems to me that without access to the car, or someone at the other end with a Subaru compatible scanner/logger that they can use and interpret, we're back to speculating, guessing, reporting on similar past experiences and all the other methods we use to try to be helpful from a distance. I don't think we can avoid this. It's a form of 'brain-storming" -- not judging, but putting ideas out to list, because at some point they could be relevant to the process. And, it often works.

 

[cardoc]

DTC(s) please

 

[eandsphotography]

Just an update. Brought it in to the shop yesterday and had a cylinder misfire code on 3 and 6. Did a tune up and changed the plugs and cleaned the throttle body and changed fuel filter and it's running great again. Was hoping that it wasnt the coil packs and so far it seems like maybe it was just due for a tune up. Gonna drive it this week and see how it acts.

 

[cardoc]

Great. Coil packs on the H6 are tough and long lasting. Never replaced one on any of them, mine or customers and mine has 178k on it.

cleaned the throttle body

Just a note for future reference: When you get a TPS code on these cars, clean the throttle of any carbon first before replacing the sensor. The carbon build up will prevent the plate from seating and the PCM will think the TPS is sending erroneous info at closed throttle.