Ongoing evap CEL

[Nolfol]

It’s started out months ago as incorrect purge flow .
so replaced both solenoids ,gas cap,pvc valve (do to mileage) So that corrected it until week later ... small leak popped up
Re checked fitting etc ,
Decided to bring it the dealer for smoke test found no leak ,they thought it was bad rear solenoid I just put in ...they ordered another .
Another trip there oops It’s not the soleniod now they found a leak in filler tube they took a video of it during smoke test .
so they order new one And replace it re test it all good no leaks
Cell still on for gross leak
They call corporate tech support .they say to weigh the canister if it’s over 3.5 pounds replace it
Mine weighs 3.0 ...
If not that it needs new pcm
So now I’m into this evap issue for $730(my parts and there parts +labor)
and now they want $1200 for new pcm without labor
Any body have similar issues ? I searched but couldn’t find similar

 

[Nolfol]

not much traffic here ......this site not like most forums

 

[pmckechnie]

Nolfol, It may get more responses if you told us what car you are working. In spite of what some think, every car is different in some way.
For instance, I have a 2018 G80 Base with 3.8 V6 RWD . A 2012 Genesis 5.0 ultimate will be different.
Error code would help also.
This is food for thought for every one on this forum.

 

[Nolfol]

Nolfol, It may get more responses if you told us what car you are working. In spite of what some think, every car is different in some way.
For instance, I have a 2018 G80 Base with 3.8 V6 RWD . A 2012 Genesis 5.0 ultimate will be different.
Error code would help also.
This is food for thought for every one on this forum.

Thanks for the response... as I posted it in th BH PLATFORM discussion thread
thought it might be obvious but more info is needed then here it is
The V8 and the V6 share the same evap Components but I have a 5.0
code is p0455 gross leak
But no leak is present with all new components
That’s why the dealer believes it needs new computer
Just curious if others have run into any similar evap problems thanks

 

[Nolfol]

Nolfol, It may get more responses if you told us what car you are working. In spite of what some think, every car is different in some way.
For instance, I have a 2018 G80 Base with 3.8 V6 RWD . A 2012 Genesis 5.0 ultimate will be different.
Error code would help also.
This is food for thought for every one on this forum.

Thanks for the response... as I posted it in th BH PLATFORM discussion thread
thought it might be obvious but more info is needed then here it is
The V8 and the V6 share the same evap Components but I have a 5.0
code is p0455 gross leak
But no leak is present with all new components
That’s why the dealer believes it needs new computer
Just curious if others have run into any similar evap problems thanks

 

[Nolfol]

Lol not sure why it double posted

 

[mikec]

Anybody think to check the pressure sensor mounted to the fuel tank? This is how the computer monitors the evap system. The computer expects to see pressure slowly drop as fuel is drawn out of the fuel tank - a vacuum will build up. Once vacuum reaches a certain level, the spring-loaded poppet valve in the gas cap opens to let fresh air into the tank. The computer monitors the tank vacuum level, expecting to see what amounts to a saw-tooth shaped pattern. If it doesn't see that pattern you get the error light. The computer can't really tell the difference between a big leak and a bad sensor.

Leaks at the Canister Close Valve or the Purge Control Solenoid Valve let air backflow into the canister and fuel tank when the engine is OFF which will read as large leaks. Those valves exist to isolate the canister and fuel tank when the engine is off; when the engine is running the Purge valve lets engine intake manifold vacuum suck trapped gas fumes out of the charcoal canister to clean it. The valves are fairly easy to test with a vacuum pump + guage (e.g. a MityVac) and 12 volt power source.

There is a vacuum hose between the fuel tank and the vapor/charcoal canister. Pinching that shut at the fuel tank end (if possible, otherwise wherever you can access it) will isolate much of the system. If the error persists, that indicates a leak at the tank, at the fuel filler assembly + hose, or a kaput sensor. If the error can be reset and stays OFF, then the problem is downstream of that vac hose, the charcoal canister, or under the hood somewhere. Pinching this line lets you split the system in half to aid diagnostics...

mike c.

 

[pulsar]

Odd the dealer wants to replace your PCM? I think they are fishing. I’ve replaced charcoal canisters and purge valves before in another vehicle when I had evap codes present. Both were between the fuel tank and aft firewall so tight area to work in. Normally the CEL will get you pretty close for components needing replacement so surprised the dealer is having issues pin pointing root cause?

 

[Nolfol]

thanks for the suggestions
Ya I’m baffled
I replaced the Both solenoids at the motor and inthe rear Changed the gas cap and pvc valve
And the fuel pressure sensor
All OEM Hyundai parts
The dealer has changed the filler tube and now smoke tested it three times and vacuum tested all part separately only thing that hasn’t been changed is the canister but they want to
even though it’s been weighed and is under spec
But also said it’s just let see kinda thing
at this point I’m going to change it myself for a shot In the dark But most likely wasting $
I keep thinking it’s something stupid that’s being overlooked
Car now has 138k on it
Funny thing is this all started a week after my transmission was replaced for the second time
And I asked them if they may have hit a vacuum line and they said (dealer) there not any where near the trans

 

[FloridaGuy]

This may help, maybe not. Hyundai identifies the P0455 as an air leak in the fuel filler area. I know you have replaced the cap and they replaced the filler tube...I would double check the filler tube, joint hose. Good Luck and let us know!

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[Nolfol]

2013 5.0 Rspec
Update :re checked all fitting and replaced canister too ....did a smoke test myself couldn’t find any leaks and all checked all fuses etc
I did notice a hissing with a stethoscope on my upper intake manifold yesterday it wasn’t that loud figured it was just vacuum noise but also wouldn’t that throw a different code ?
Think I‘m reaching Lol
pulling my hair out trying to fix This issue Still P0455 code every 150/200 miles just keep clearing it May come down to changing tcomputer and see if it fixes it !$$$

 

[gregm]

I just got the same code this morning. 2013 5.0 Rspec. I guess i'll start investigating this weekend. I got the first light about 2 months ago. I took the fuel cap off and put it back on. The code just reappeared this morning after sitting overnight after a few minutes of driving.

 

[Nolfol]

I just got the same code this morning. 2013 5.0 Rspec. I guess i'll start investigating this weekend. I got the first light about 2 months ago. I took the fuel cap off and put it back on. The code just reappeared this morning after sitting overnight after a few minutes of driving.

Hopefully yours is an easier fix than mine
Just had the dealer order the new PCM

 

[Michael23v]

Same issue on a 2013 5.0 R-spec. Anyone find a fix yet?

 

[G-757277]

Same issue on a 2013 5.0 R-spec. Anyone find a fix yet?

still waiting on the part to come in gotta love pandemic shipping
Have u replaced anything yet ?

 

[Nolfol]

Same issue on a 2013 5.0 R-spec. Anyone find a fix yet?

Still waiting on part gotta love pandemic shipping
Have you replaced anything yet ?

 

[Michael23v]

Canister twice. The dealership is a joke. So, gonna start looking into other options, which is how I got here. Hoping we come up with something.

 

[Nolfol]

my dealer has been pretty good ,if a part didn’t fix issue I wasn’t charged for it or the labor .
But Got an email parcel damaged in shipping returning to sender so now I have to wait more time for the pcm ...ugh
Michael did they smoke test it?
The The two solenoids are easy to change
And gas cap is cheap you can do them yourself
Can’t hurt

 

[MG8]

got this same issue right now on my sisters 2009 replaced gas cap, purge valve, canister close valve, and fuel pump gasket and plate did smoke test could not find anything and it is still throwing code.

 

[MG8]

we still cant find what is wrong with this thing it will pass test 5 times then fail . so far we replaced purge valve, close canister valve , all tank gaskets, fuel pressure sensor . im leaning towards a ecu now but damn thing is on backorder with no release date .