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Hard to start after getting gas

my 2002 subaru legacy sometimes is hard to start and keep going after filling up the gas tank. But after several miles runs fine - starts fine until needing to put more gas in the vehicle.



also recently it has started to seem like it is a little jerky & sluggish going up hills



any suggestions?

Fuel pump, fuel filter, gas cap or vapor recovery system (do you top off the tank when you fill up?)

This does sound like the type of problem that results from forcing more gas into the tank after the pump at the station clicks off for the first time. That is why there is a warning on the gas cap about not overfilling the tank.

If this tank has been overfilled repeatedly, it is very possible that it will be necessary to replace the carbon canister or possibly a solenoid valve in the evaporative emissions system. For the sake of your wallet, pray that you don’t have to replace the carbon canister.

Alternatively, it is possible that the fuel filter is clogged. This part needes to be replaced at least every 30k miles. When was the fuel filter last replaced? If the fuel filter has not been replaced on that schedule, it is possible to kill the much more expensive fuel pump.

thanks for the reply. We did replace the fuel filter last night and haven’t gotten any gas as yet. The old filter looked pretty clean so I don’t think it’s been too long on the car.

It did take me awhile (more than several years) before I noticed the warning on the gas cap about not overfilling but I stopped doing that once I realized it and the trouble started happened six months??? after I quite topping it off.

Do you know if my vehicle has a mass air flow sensor that if it is dirty could be causing my intermittent stuttering going up hill? If it does, do you know where it is located?

Do you have a check engine light on? If your MAF is bad it should show up if you pull the check engine codes.

yes - my check engine light is on more than it’s off but that’s been a recurring thing since I bought the vehicle which makes sense if I kept overfilling the gas. I live several hundred miles away from the dealer and the mechanics in our area are about only good for oil changes. When I took it to the dealer recently, they said there were too many different codes for them to determine what the trouble was. They recommended that I get the vehicle in to them when I can keep it there for several days but with working M-F it’s difficult to get it to them for multiple days. Guess I’m just going to have to make the time to take it to the dealer for several days. Thanks again for your response.

…Sigh…

Once again, someone decides to leave out the detail regarding the CEL until we actually question him/her about it. This is sort of the automotive equivalent of going to a doctor, telling him that you don’t feel well, but leaving out a detail like shortness of breath and crushing chest pain. Just as the doctor has no clue how serious the situation might be due to lack of vital details, we also have a very hard time with a diagnosis.

And, since the dealership claims that there are “many different codes”, this car is probably a very sick patient. Trying to “cherry pick” a solution to the stated problem is futile at this point, especially over the 'net.

This car has likely had very little maintenance, and is now suffering from that laxity. The OP is just going to have to bite the bullet and have the codes read by a competent mechanic. Just be prepared for a very big bill, because repairs are far more expensive than timely maintenance.

Kevin , your post is unclear but it does not matter as this thread is 9 years old.