10frank9

So for the past few months I've been battling the dang check engine light coming on even after a reset. Got the 0456 code and found out that it was the emission/ evap system "small leak." Most folks, including my mechanic suggested starting at the gas cap.

Big surprise, it came back on after a few hundred miles. I checked all of the evap/vacuum lines (or so I thought) and couldn't find the source. I read somewhere that the battery sometimes corrodes a vacuum line which is right next to it. I checked it and sure as hell, small hole from the battery acid or heat. I did a quick cheap and temporary fix in order to diagnose if that was the source of the code popping. I taped the line up with some electrical tape, and 500 miles later, still no codes popping! Thought I'd share this for anyone else who may be dealing with this frustrating code popping and likes to DIY. I'll be replacing the line soon, and figuring out a way to reroute it or shield it from the battery acid.

Once you see where this darn thing is you'll wonder what they were thinking putting it there in the first place. Anyhow, hope this helps someone.

Stay dirty my friends.

jkfisher84

Wow thanks! Mine must have been the gas cap cuz the light stopped coming on but ill take a look at what your talking about just in case!

Hohertz

Looks like I have the same issue. At first it was just my "gascap" light that came on last week and then this morning I noticed I had both my gascap light and the check engine light come on. I've re-tightened the gas cap and reset the indicator light but they both came back on after starting the engine again. So I ran a diagnostic and got codes P0456 P0457 along with "gascap". When I get home tonight I plan to take a look at the lines near my battery and the evap can itself. Hopefully mine is as easy of a fix as your was. Thanks!

10frank9

Well I hope it is too. Wound up cutting out damaged part of the line and replacing it with a small rubber tube. Close to 800 miles now and no code popping. Let me know if I can help any further, pics etc..

Hohertz

No bueno, doesn't look like I'm so lucky. I got under my hood on Monday night and found the tubes right by the battery and ran my fingers all around the sides of them but couldn't find any area that looked/felt to be too worn..... I followed them as far as I could and it all seemed to look alright. But I'm still getting a "gascap" indicator and the check engine light is still on. I get codes P0456 and P0457 when I run a diagnostic.

Tonight I'm going to crawl under and take a look at the evap can itself and see if I can spot anything. Do you happen to have any other clues as to what I can look for? Were your tubes near your battery worn to the point of creating a hole? Thanks

DeucesALLin

Electrical tape fix here too.

Hohertz

Was yours worn through to the point of having a hole? Where was it at?

Maybe I try just wrapping the tubes in electrical tape....

10frank9

When I felt the line it just felt rough and a bit worn. When I cut it it was obvious it literally had a pin size hole. Here is a picture of the hole in the line once it was removed (cut). Btw it was on the line closest to, and actually touching the battery. Acid just corroded a pin sized hole, enough to pop the code.



Attachment 345673

Hohertz

I gotcha, thanks alot for the reply and picture. I'm gonna wrap it up in electrical tape to see if that does anything because I could feel a slightly worn area when checking the tube but couldn't feel a pinhole... might have missed it.

Did it immediately fix the check engine light for you?

ATXFIREMAN

Electrical tape worked for me. Mine wasn't worn all the way through. The shiny outer layer was rotted off giving the hose a rough powdery texture. The hole was likely a pinhole. It works though!!!