Evap Code Help!

Badshot · April 22, 2010

So i have a code p0449 and well, the guy at the part store said why dont u try driving it without the gas cap tight to see if it throws a diff code(the code thats on there + 1), if it still throws the same code then u will have narrowed it down to the gas cap. Well i thought that made some sense, What didn't make sense was, when i did this.. The SES light turned off... Wouldnt it have turned turned on, but with a different code atleast? Why is it my SES light goes off when i loosten the gas cap -_-

Badshot · April 22, 2010

Anyone help?

Badshot · April 22, 2010

Anyone help?

bump

nickvrebel · April 22, 2010

drive it more. the failure must be seen within certain drive cycle conditions.

rmck490 · April 23, 2010

So i have a code p0449 and well, the guy at the part store said why dont u try driving it without the gas cap tight to see if it throws a diff code(the code thats on there + 1), if it still throws the same code then u will have narrowed it down to the gas cap. Well i thought that made some sense, What didn't make sense was, when i did this.. The SES light turned off... Wouldnt it have turned turned on, but with a different code atleast? Why is it my SES light goes off when i loosten the gas cap -_-

I would bet the light turning off didn't have anything to do with the cap being off. The EVAP test that tripped the p0449 code initially ran again and PASSED so it shut the light off. The code is now stored in the history memory for the next 40 drive cycles waiting for another test failure. It takes two test failures to trip this code and turn on the SES again. You may have an intermitent problem. From what I've read, this code is a Vent Valve circuit issue.

Like NickV says, keep driving without the cap on and see which condition pops the next code. You'll get a different code for a large EVAP system leak with the cap off/loose.

I've been driving for a week with the SES on for a p0446 code. It comes and goes and sometimes I reset it just to shut the light off. It's just an EVAP code that's not hurting anything unless you live where you have to pass emissions. One of these days I'll try to trace my problem and finally fix it.

Badshot · April 23, 2010

So i have a code p0449 and well, the guy at the part store said why dont u try driving it without the gas cap tight to see if it throws a diff code(the code thats on there + 1), if it still throws the same code then u will have narrowed it down to the gas cap. Well i thought that made some sense, What didn't make sense was, when i did this.. The SES light turned off... Wouldnt it have turned turned on, but with a different code atleast? Why is it my SES light goes off when i loosten the gas cap -_-

I would bet the light turning off didn't have anything to do with the cap being off. The EVAP test that tripped the p0449 code initially ran again and PASSED so it shut the light off. The code is now stored in the history memory for the next 40 drive cycles waiting for another test failure. It takes two test failures to trip this code and turn on the SES again. You may have an intermitent problem. From what I've read, this code is a Vent Valve circuit issue.

Like NickV says, keep driving without the cap on and see which condition pops the next code. You'll get a different code for a large EVAP system leak with the cap off/loose.

I've been driving for a week with the SES on for a p0446 code. It comes and goes and sometimes I reset it just to shut the light off. It's just an EVAP code that's not hurting anything unless you live where you have to pass emissions. One of these days I'll try to trace my problem and finally fix it.

So today i drove it quite a bit.. and tightened and loostened the gas cap about 5 times... everytime i tightened it, The light came on Still for p0449. When i loostened it.. the light shut off. After doing this all day i have come to realize, i dont think its just a Coincident it turning off, especialy when it did it 5 times today. So Hm now what?