P0456 Small Evap Leak

[bowlofturtle]

Had this code for a while now on the 03 Lancer. Never bothered doing anything but emission testing is soon and a CEL is Fail on the spot.

The Lancer is powered by a 2.0L SOHC motor with maybe 110k. CEL is on, i noticed a little stumbling at idle once in a blue moon, might be related or not.

Cleared the fault, it comes back after a few drive cycles so obviously its a real fault. I did the cheap and easy route, got a new gas cap. Carquest branded, made in the USA from AAP. At the same time i removed and tested the "evap purge solenoid valve" the one in the engine bay. Applied 12v and heard/felt a click, tested the resistance it was 33ohms (spec is 30-34ohms @ 68F).

Cleared the fault after new cap and confirmed one valve is good. Drove 2-3 drive cycles and back again P0456.

Next up should be checking the valve at the canister and other lines near the canister.


Any other suggestions? Every time i've had a evap related fault it was always the engine bay valve, the valve would be stuck open or closed. This is my first out of like 9 cars i'ved messed with not to need a evap purge solenoid or a completely broken charcoal canister.

Is there a cheap DIY smoke machine method i can do.

 

[Falcon_LS]

Check the lines, I had a hose dry up and crack which triggered it.

 

[Merkava_4]

The easiest thing to do is pay someone to smoke it for you and then you change the part at home.

 

[bowlofturtle]

Originally Posted By: Merkava_4
The easiest thing to do is pay someone to smoke it for you and then you change the part at home.


Its always the easiest thing to do. If i do pay someone, at that point i might as well pay them to finish the job and make sure it done right. Because R/I of the parts is probably 1 hour flat rate for anything like the canister or the other valve.

I'm trying to do anything and everything i can prior to taking it in.

 

[Merkava_4]

Originally Posted By: bowlofturtle
Its always the easiest thing to do. If i do pay someone, at that point i might as well pay them to finish the job and make sure it done right.


Not necessarily. You can save alotta money by just paying the diagnostic fee and then doing the labor yourself. Most of the expense is in the labor, and then some shops jack up the prices on the parts too.

 

[bowlofturtle]

Originally Posted By: Merkava_4
Originally Posted By: bowlofturtle
Its always the easiest thing to do. If i do pay someone, at that point i might as well pay them to finish the job and make sure it done right.


Not necessarily. You can save alotta money by just paying the diagnostic fee and then doing the labor yourself. Most of the expense is in the labor, and then some shops jack up the prices on the parts too.


Some cars repair yes. But this one isn't the case. All parts that are possible causes are easily seen and able to be touched. Charcoal canister is right under the bumper. Crawl under and see it. Evap sensor right in the engine bay.

I think its time to send it to the shop.

 

[Leo99]

Next up should be checking the valve at the canister and other lines near the canister.

Did you do this? I changed out my canister/valve and it fixed my problem.

 

[Silverado12]

My advice is do not throw parts at it. Check all the vac hoses in the system, around the vent valve, etc. Then have it smoked if you can't find any cracked hoses, etc.

 

[demarpaint]

Originally Posted By: Silverado12
My advice is do not throw parts at it. Check all the vac hoses in the system, around the vent valve, etc. Then have it smoked if you can't find any cracked hoses, etc.


Exactly.

 

[Darris]

Don't be too shocked if you don't find anything. These systems are oversensitive to begin with and can really react to imaginary leaks once they're 10 years or older. Both of my Altimas post this code all the time as well as PO1491.

I've spent time with my mechanic on multiple visits, we inspecting it, smoking it, spraying it, thermal-imaged it ... nothing.

Supposedly the code should come up if the condition presents twice the space of 40 drive cycles. But often times it seems to return in far less than 40 drive cycles. It's also supposed to clear itself after any 80 consecutive trips without detecting the leak - but it never does - yet I can often make it go away with a specific routine of filling it 4/5th full and driving 80mph with the AC on. Sometmes it stay off for 400 miles, other times it comes back in just a few trips (none of which was a proper drive cycle...)

 

[SHOZ]

I just replaced the purge valve on my Hyundai Accent. Got the P0456 but the real indicator was hard starting after filling up with gas. The solenoid worked on it but there is garbage that builds up and keeps the valve from fully sealing when off.

 

[Darris]

Originally Posted By: SHOZ
I just replaced the purge valve on my Hyundai Accent. Got the P0456 but the real indicator was hard starting after filling up with gas. The solenoid worked on it but there is garbage that builds up and keeps the valve from fully sealing when off.

What kind of hard start? You mean like with a normal turn of the key but a slight delay and then an abrupt kick in, or actually requiring you to hold the key turned all the way for an extra second to amke it turn over?

 

[SHOZ]

Originally Posted By: Darris
Originally Posted By: SHOZ
I just replaced the purge valve on my Hyundai Accent. Got the P0456 but the real indicator was hard starting after filling up with gas. The solenoid worked on it but there is garbage that builds up and keeps the valve from fully sealing when off.

What kind of hard start? You mean like with a normal turn of the key but a slight delay and then an abrupt kick in, or actually requiring you to hold the key turned all the way for an extra second to amke it turn over?
It would crank and not start unless I pumped the gas and held the pedal down. Only did it after getting gas. They say on Hyundais the valve gets plugged with rust.

Had a mid 90's Taurus and the valve would get a waxy buildup in it.