Outback misfires in the cold

Maintenance/Repairs
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1

My 2003 Subaru Outback wagon misfires when it is very cold (below zero) and has been sitting for 6 or more hours outside (where I have to park at my work). I have had it towed 3 times to our mechanic but they can’t get it to misfire.

I even called from the parking lot to verify with them that it was misfiring, and they said not to drive it, but have it towed in. If they can’t find anything wrong, how can I prepare for this winter? I don’t want to be stranded.

2 
When was the last time you changed the plugs and wires?  (if you don't know, now would be a good time.)  Don't use the fancy expensive plugs or wires, use OEM quality and brand if you can.  

I would also suggest a can of DryGas type product. Long cold exposure could freeze any moisture in the system and cause the problem you are observing.  I also could consider changing out the fuel filter if you can't remember when it was last done.
3

Is a check engine light on? If so, get the codes read for free from a local auto parts store that will do this.

4

Thanks for the suggestions…I will check my records and make an appointment. The DryGas worked a couple times, so I keep a bottle in the car just in case.

5

The check engine light is not on. But thanks for the reply.

6

That seems very odd that you have misfiring but no check engine light. There may be codes stored even though the light’s not on.

7

Thanks for the suggestion. I’ll have it checked.