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Mike V.
Mike V., Subaru Technician
Category: Subaru
Satisfied Customers: 25201
Experience:  Certified Subaru Technician, factory trained by Subaru.
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2002 Subaru Outback: it hesitates..occurs only on the drive home

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I have a 2002 Subaru Outback. The issue is that it hesitates after I fill it up with gas. This occurs only on the drive home after filling it up. After it sits for the night it's fine the next day. This issue occurs throughout the year -- in colder weather and warm.
Greetings Sir or Madam and welcome to JA! I will do my very best to assist you with your problem.
Hi there!
Is the check engine light on or come on when the issue is occurring?
Do you have any trouble starting the car after filling it up?
Customer: replied 5 years ago.

The check engine has been on once in the past year and did not produce a code when I took it to Autozone. I tightened the gas cap and the light hasn't come on since. The hesitation in acceleration has occurred consistently after each gas fill up for about a year. The engine light code may be related, but I'm not sure and it is very infrequent relative to the hesitation (again, only once in the past year).

The car never has an issue starting whether it's after filling gas or not.


Ok, the only issue I can think of that may be related is some type of issue with the purge control valve. If it is sticking open a bit, when you fill the car it might be allowing to many fuel vapors into the mixture. This could give the car to much fuel and sort of flood it. This could cause rough running, a hesitation from starts. Things of this nature.
The other thing I do see that causes this type of thing is a faulty front O2 sensor. Normally however it wouldn't just be related to adding fuel to the car. This is more consistent in most cases.
The purge control solenoid allows intake vacuum into the evap system to suck the fuel vapors out of the canister under the car. I really see no other connection between fueling the car and the hesitation.
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