check engine light on, then off

[loonmobile]

After dropping $600 at my Subaru dealer two weeks ago when the Check Engine light came on, (the 3rd cyliner misfired, whatever that means), it went on again yesterday after being parked on a steep slope in my driveway with near zero temperatures (wind chill 20 below). On the way to the Subaru dealer this morning to check it out, the check engine light went out. I still proceeded to the dealer for checking. That's where the car is now.

 

Any ideas what this might be?

 

Note: Somebody told me a defective gas cap could cause the check engine light to go on. I seem to remember the gas cap used to "click" after replacing. It doesn't click anymore.

 

model: 2001 legacy wagon

 

Thanks!

 

hu

[nipper]

After dropping $600 at my Subaru dealer two weeks ago when the Check Engine light came on, (the 3rd cyliner misfired, whatever that means), it went on again yesterday after being parked on a steep slope in my driveway with near zero temperatures (wind chill 20 below). On the way to the Subaru dealer this morning to check it out, the check engine light went out. I still proceeded to the dealer for checking. That's where the car is now.

 

Any ideas what this might be?

 

Note: Somebody told me a defective gas cap could cause the check engine light to go on. I seem to remember the gas cap used to "click" after replacing. It doesn't click anymore.

 

model: 2001 legacy wagon

 

Thanks!

 

hu

 

yes a bad gas cap can make it go on. It should click at least three times. Extreeme cold weather can make cars do odd things untill warmed up. You can have a weak sensor that the cold weather just made go out of its parimeteres and throw a code. If thats the case, the dealer should keep the car over night and check the codes then.

This is something that i wouldnt necassarily get annoyed with the dealer for.

 

nipper

[loonmobile]

yes a bad gas cap can make it go on. It should click at least three times. Extreeme cold weather can make cars do odd things untill warmed up. You can have a weak sensor that the cold weather just made go out of its parimeteres and throw a code. If thats the case, the dealer should keep the car over night and check the codes then.

This is something that i wouldnt necassarily get annoyed with the dealer for.

 

nipper

 

Just heard back from the dealer. He said the "throttle box" was a little "gummy" and might need a cleaning. This is why the check engine light went on (then off). He didn't mention anything about the gas cap. To clean the throttle box we're looking at about an hour for labor. My wife gave the go ahead to do the work.

 

Have you ever heard of a dirty or gummy throttle box?

 

Should we get a new gas cap?

 

Thanks again!

 

hu

[mwatt]

Just heard back from the dealer. He said the "throttle box" was a little "gummy" and might need a cleaning. This is why the check engine light went on (then off). He didn't mention anything about the gas cap. To clean the throttle box we're looking at about an hour for labor. My wife gave the go ahead to do the work.

 

Have you ever heard of a dirty or gummy throttle box?

 

Should we get a new gas cap?

 

Thanks again!

 

hu

 

Correct name for that is a throttle body. It's the part on the engine that the accelerator cable attaches to. Yes, a throttle body can become plugged up with deposits. It might be helpful if you could ask the dealer what code they obtained when they scanned the car's computer. (They did do that, right?)Even though the "check engine" light may have gone off, the computer retains the code.

[edrach]

If you have doubts about the gas cap, replace it; it's not that expensive and will put your mind at ease....and might even prevent a recurrence of that pesky check engine light.