I love my WRX but I have one nagging problem. I keep getting this check engine light triggered by the what the OBDII checker is saying is a loose gas cap. I get it checked at AutoZone and they look at me like a moron and tell me to tighten my gas cap and they reset the light. I drive for 3 or 4 days and it comes on again. I get it checked again and they tell me the same thing. I go buy a new gas cap and it is still doing it. It dosent seem to effect performance in anyway but the light is annoying and I'm getting sick of people getting in my car and going "do you know you have a check engine light on". I-club genius unite and please help me figure out what the %$@# is the deal with this.

 

I don't have much info to tell you what is wrong, but if it is continously happening, then you should take it into the dealer to get it checked out.

 

Is your car lowered? Since the pipe for the gas tank runs along the fender well it may have been punctured.

 

I have this EXACT same problem! I'm glad to hear that it's not just me. I don't know what to do about it either. My light just came on again last week, so I need to take it in have have them actually fix the problem instead of just clearing the code.

My suspension is completely stock.

I'm very interested to see if someone can shed some light on the situation.

 

i have had that problem for a year now and taken it in about 4 times specifically for that


basically subaru just tries to blame it on other things instead of taking the time to figure out what the problem is. my light is still on.

i just assumed i am going to live with this problem forever

 

the first problem is that you're having autozone check it out. get the dealer to look at it - hopefully they can find a fix.

 

i would be happy to take it to a dealer except its $85 a pop just to plug it into the same thing that AutoZone has. My warrenty is WAY past expired so thats out.

My car is 100% stock EXCEPT for a Progress rear sway bar but it was doing this before that.

It's nice to see I'm not the freak here also. My Grandma has a 03 impreza outback and she had a faulty gas tank (when they made it there was a bunch of metal shavings in the tube that prevented here from fiulling the gas tank in any time less than 15min) so Subaru isn't inocent of matters pertaining to this. I really hope someone can figure this out.

 

It would help to post the actual numerical code you are getting.
There isn't really a specific "gas cap" code. The ECU regularly tests the fuel tank and evaporative emission system for integrity and ability to hold pressure, if any leaks or malfunctions are detected a code will be set. There are many different codes related to the evap system. A loose gas cap will prevent the fuel tank from being properly pressurized so it will result in a code being set, however the ECU doesn't know whether the leak is from the gas cap or something else, all it sees is a leak someplace.
It's possible you have a leak or faulty component elsewhere in the system and the gas cap has nothing to do with it. The code can help narrow it down, but a number of things may need to be checked- hoses, vent valves, solenoids, fuel tank seals etc.

 

ill get it today

 

maybe its your fuel pump.

 

i hope so because that means I can get the VF34/pump/injector combo gruppe-s has that I have been begging the wife for.

 

i'll tell you what it is

its p0457

evap system leak in the filler neck (loose gas cap)

 

That's exactly right

 

I had this problem and got it fixed. First time dealer told me to make sure I put the cap on right. Next time it happened I took it to a dealer in Nashville and they replaced the gas cap. Third try I took it back to Nashville and they did a compression test on the emissions system, found a leak in a hose and replaced it. +300 miles and several weeks later the problem seems gone.

Take your car to the dealer and tell them the problem. They should do a compression test on the emissions system. I can't remember and I'm too lazy to get the paper work right now but I think I remember something about a purge solenoid.

 

they did a compression test on mine and didn't find a leak at all and i still have the problem to this day. it has been just over a year now