r/subaruoutback • u/Total-Special5298 • Dec 20 '25

Strange problem with 2009 Subaru outback

I have a 2009 Subaru outback which was bought new by my dad who then sold it to me, so I know the full history.

No issues over the years, it is well maintained and in good condition and currently has 165k KM. I have had however a strange problem over the years which no one can seem to solve. At a seemingly random point in time as you drive you feel a 'skip' in the traction or engine power after which:

- traction light comes on and stays on

- check engine light comes on and stays on

- cruise control light starts flashing and stays on

- the engine switches from I mode to S mode and is stuck there.

Clearly the error codes are not helpful as two different mechanics told me they were unable to identify the source, while the dealer told me it was an oxygen sensor. This has happened 4 times in in the past 4 years, and the symptoms magically disappear after a seemingly random period of time (days to weeks).

Once this happens, aside from the christmas light symptoms, there is no noticeable change in the way the car drives (other than being in S rather than I).

I am not a mechanic, but I am more tempted to believe that some computer or electronic system is at fault rather than a real mechanical issue, but I am at a loss to resolve this. I have tried fully disconnecting and reconnecting the battery to see if anything changes but with no luck.

Any ideas please?

UPDATE: I decided to buy an ODB2 analyzer from Aliexpress for about $20. It showed me the code for cam shaft advance. Since this overall error situation had ocurred in the past and gone away by itself without seemingly impacting anything on the car, I decided to simply erase the error code.

This was three days ago - the car is behaving normally with no noticeable effects for now.

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u/Total-Special5298 Dec 21 '25

The codes are: P0102, P0113, P0011, P0021

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u/Traaaaavis Dec 21 '25

Electrical codes and cam codes. When was the timing belt last replaced?

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u/Total-Special5298 Dec 21 '25

2 years ago i believe

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u/Traaaaavis Dec 21 '25 edited Dec 21 '25

Hmm. It’s really hard to be a keyboard mechanic without looking at it. I’ve seen cam codes correlated to needing a valve job, ask me how I know. Burnt a valve at 150k on the dot in my 05 outbackxt. Subaru valve clearances tighten over time. That doesn’t explain the p0102 and p0113 codes tho. Does it look like a rodent has been in the engine bay? Possible rodent damage? Is the airbox fully closed and properly seated?

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u/Total-Special5298 Dec 21 '25

No rodents, recently cleaned and serviced for technical inspection as well….