Just got a used 2006 Suby -- P0171 code

[phildog33]

Hey guys

 

Just got a used 2006 Suby and after 20 miles driving it on the freeway I got a P0171 code.

 

Its a non turbo wagon, just regular, and not sure where to start with this.

 

I have 1 month before it needs inspection (currently on dealer plates) -- But what would you recommend I check for first? Need to pass inspection in February, so have a little time.

 

- Dirty MAF sensor?

- Air filter issue

- air leak in one of the hoses or O-rings somewhere = smoke test?

 

Thanks guys, if you had this problem before... maybe you can let me know where to check for problems first?

 

Phillip

[Febreze Mee]

Sounds almost like the dealer you bought it from hid this issue, and screwed you with a wire brush, if you ask me.

 

Are your MPGs losses the only issue you have noticed? Or is the car idling rougher/stalling?

 

A quick google search reveals this: https://www.700r4transmissionhq.com/p0171-subaru-outback/

 

In my experience with this code, its usually an O2 sensor. But I begin with cleaning the MAF really well, then checking for vacuum leaks. Old, brittle vacuum lines, maybe. A broken plastic junction between vacuum lines. Disconnected lines entirely.

 

Use google and type in your issue with "legacygt" behind it. Or even "subaruoutback.org"

 

If you don't do that, then at least make a search through the forum using the search function, this has been covered in multiple threads.

[Max Capacity]

I just read one of the on-line threads about this and the issue was a torn air filter.

 

Cleaning the MAF if your 2.5i has one is easy and cost a can of MAF cleaner from the auto parts store.

 

FWIW, I clean my MAF every Fall before Winter gets here. A quick spray from the can.

[jarey]

To jump on this thread, I've also got a 2006 wagon (MT) that just gave me a nice P0171 as I was idling in a parking lot today. Any chance that an exhaust install would cause the code to pop up? Swapped out the old, rusty exhaust with aftermarket fart cans for a generally non-rusty stock catback from a 2008 sedan just the day before, though I didn't get the CEL until now. No noticeable difference in driving or idling otherwise, though it's not the smoothest ever (it never really was).

 

Percussive maintenance occurred, so it's possible something just gave way, but I can't shake the feeling that somehow this return to stockness has awoken something in my car...

[slaminal]

To jump on this thread, I've also got a 2006 wagon (MT) that just gave me a nice P0171 as I was idling in a parking lot today. Any chance that an exhaust install would cause the code to pop up? Swapped out the old, rusty exhaust with aftermarket fart cans for a generally non-rusty stock catback from a 2008 sedan just the day before, though I didn't get the CEL until now. No noticeable difference in driving or idling otherwise, though it's not the smoothest ever (it never really was).

 

Percussive maintenance occurred, so it's possible something just gave way, but I can't shake the feeling that somehow this return to stockness has awoken something in my car...

 

Honestly, I have experienced a break in the hoses near the charcoal canister in the rear wheel wells that have tripped that code. That might be worth checking out.

[zactek]

I had that code and checked the maf, 02 sensor,smoke test and it wound up to be a rotted out flex section on the cross pipe in the exhaust,sucking too much air before the 02 sensor. Bought a new Grimmspeed cross pipe and the code went away.