That's the worst code ever and can be anything from the gas cap to the little lines that run from the evap canister. People go to great lengths to diagnose it sometimes, and sometimes they get lucky just replacing the gas cap. A smoke test is needed should the gas cap and visual inspection fail to show the problem.

It wouldn't hurt to just clear the code first and see if it comes back. If it does then replace the gas cap and clear the code again. If that fails to fix it, then you have a rodeo on your hands trying to figure it out. On my 1997 Jeep Wrangler I replaced all of the lines, because they were rusty. I've never gotten the code again with the OEM gas cap, so I got pretty lucky.

 

That's the worst code ever and can be anything from the gas cap to the little lines that run from the evap canister. People go to great lengths to diagnose it sometimes, and sometimes they get lucky just replacing the gas cap. A smoke test is needed should the gas cap and visual inspection fail to show the problem.

Thanks Robert for the "good news".
Yeah, what I did is order a gas cap on Amazon (said its as good as an OEM) and a code reader, so I dont need to go back to Advanced auto for the codes anymore. I'll put the new one on, clear the code and see what happens.

 

I put a new gas cap on. I bought a cheap lil scanner, it is showing... Fault: 01 and Pend: 01
Is the scanner bad? I turned the key, not starting the vehicle and this is what is showing.

 

Well, at least it’s telling you that there’s a fault code… does it not give you the actual code?

 

Here is all I can get out of the dang scanner...may return it. It says fault 01, fault 02, I push "enter" and get this.

scanner-1 hosted at ImgBB

Image scanner-1 hosted in ImgBB

ibb.co

scanner-2 hosted at ImgBB

Image scanner-2 hosted in ImgBB

ibb.co

scanner-3 hosted at ImgBB

Image scanner-3 hosted in ImgBB

ibb.co

 

B2aaa on your scanner is an error code, it’s not communication with the car properly. It probably helps if you read the instruction. I’ve found over the years that some OBDII code readers do not work with Fiat more than other makes.

 

Yeah, going to return it. Its not compatable with Fiats. Back to looking for another one.

 

Okay ladies and gents. Have good news to report.
I didnt want to wait on the new code reader to arrive to "erase" all codes, so I disconnected the battery for 5 minutes. While it was disconnected, I cleaned the gas filler neck with a rag and WD40. I already installed the new gas cap. Reconnected the battery and walla...engine light was the first one to disappear before all others went out! (well, except for a bad inflation sensor in the left front tire, but thats for another day). I'm not cancelling the order on the new bluetooth code reader, I may need it down the road.

 

If you have an Android phone you can get the "Torque" app and "Fiat Advance" add on for cheap. Along with an ELM327 blue tooth adapter you'd be all set for less than $20.

 

I already ordered the Bafx Bluetooth scanner. It's supposed to be even more compatable than the ELM. Was a couple bucks more than the ELM. Will check into the Torque app. Can I use the app without the "advanced" add on?

 

Dunno. Fiat Advance was only $5 add on to $5 Torque app. ELM is a no brainer/no issues at $8. Works great and helped me resolve common issues like gas cap and get transmission temperature for a fluid change and replace a thermostat.

 

Have a pressure test performed on you evap canister. If you continue to have the issues, after resetting the code. When my car was new, a replacement gas cap wasn’t the issues.

 

Hmm. That scares me a little. I didn't know we have a "check fuel cap" warning readout. I notice in the photo no check engine light, which makes sense. I was focused on just the check engine light. Well, so far, it's still off, after driving a few miles today.

 

i currently have the P0456 as well. for me, it's a permanent DTC in that even if i clear the CEL, it will eventually come back on (and it shows as a P-DTC on my obd app when i scan for it).

i haven't really started to diagnose it, but i picked up a new Evaporative Emissions System Leak Detection Pump (Dorman part #: 310-219) for $20 as i was reading that sometimes that is the culprit. i figure being that its on the underside of the car and has been exposed to umpteen amount of winters lol its not a bad idea to replace it anyway.

happy to report if this solves it. seems like it's a quick job but just haven't done it quite yet.

 

oh, i should add that i replaced my gas cap and that did not fix it.

 

Evap canister, bad.

 

Good to know it was the evap canister. I saw a video on YT where the guy untwisted the sensor I guess it was, and replaced it. He just pulled a hose off, untwisted it and put a new one on. He didn't change the canister though. Is that underneath in between the rear wheels?

So far, I don't have any check engine light after changing the gas cap out and cleaning the rim of the filler neck with rag and a little WD40.

 

Good to know it was the evap canister. I saw a video on YT where the guy untwisted the sensor I guess it was, and replaced it. He just pulled a hose off, untwisted it and put a new one on. He didn't change the canister though. Is that underneath in between the rear wheels?

So far, I don't have any check engine light after changing the gas cap out and cleaning the rim of the filler neck with rag and a little WD40.

yep - i'm referring to this pump (it screws into the evap canister):

i still haven't replaced mine (tho i have a new one). will report back when i do

 

Okay, that's not the video I saw, but that's a good one. Looks like something that's is easy to get to at least. Keep me posted if and when you change it out. I'm not messing with mine, for now anyway, as the check engine light is still off.

 

on my '13 Lounge, I had a 0456 code (small evap system leak) and CEL, as well. I removed the cap and noticed a slight scratch on the filler neck lip. I sanded the scratch off with sand paper, cleaned the lip, and applied silicon grease to the cap rubber ring. After erasing the code via a generic code reader, the code and CEL went off and has not returned since....

 

mine either. i cleared it on 5/26 and it still hasnt come back, but it shows as a permanent trouble code on one of my apps.

i'm just waiting for the CEL to come back on (which it has after i cleared it; i tried disconnecting the battery as well and that doesn't fully clear the trouble code), as i've developed an app that has the ability to clear codes and i'm testing a certain reply condition.

what app are y'all using to check your DTCs and does it distinguish between a permanent/persist DTC and a normal one?

 

I am using the MultiECU Scan Windows program and ELM327 interface. But this time, I have not used it, after clearing the code with a generic OBDII reader. I know it is still stored, but for now, not having a CEL on is good enough. I'll take care of the stored DTC next time I hook up the MecuScan to my lap top.

 

i'm using the obdlink app with my obdlink mx+ and it shows the P0456 as a permanent dtc. i've disconnected the battery, and weeks later it came back. i cleared it, and weeks later it came back. so i looked it up online lol and the resources are saying permanent trouble codes aren't fully cleared until the problem is actually resolved.

the issue i believe is that one of the sensors is showing an error code and it simply will not be resolved until it is fixed.

not a big deal and par for the course w/automobile ownership.

if only things worked the other way lol and you could wave a wand and solve the "problem" by clearing it with a certain app

 

I tried clearing my code too, it says its "permanent" on my code reader, wont let me clear it.

 

This item may be defective:
Amazon.com: Dorman 310-219 Evaporative Emissions System Leak Detection Pump Compatible with Select Models : Automotive
But before you buy it, go under the rear of the car , up in the center areas and remove it from the vapor canister; clean everything, especially the rubber O ring, flip the O ring upside down, apply some oil or grease and reinstall the unit. It comes on and off by twisting it 1/4 of a turn. While there, take a good look at all the gas tank hoses and inspect for rotting or cracks. Then clear the code, fill the tank all the way up, and see if the problem reoccurs. This was the plan on mine but after dressing up the scratch on the filler neck, the code has not returned.

 

This item may be defective:
Amazon.com: Dorman 310-219 Evaporative Emissions System Leak Detection Pump Compatible with Select Models : Automotive
But before you buy it, go under the rear of the car , up in the center areas and remove it from the vapor canister; clean everything, especially the rubber O ring, flip the O ring upside down, apply some oil or grease and reinstall the unit. It comes on and off by twisting it 1/4 of a turn. While there, take a good look at all the gas tank hoses and inspect for rotting or cracks. Then clear the code, fill the tank all the way up, and see if the problem reoccurs. This was the plan on mine but after dressing up the scratch on the filler neck, the code has not returned.

Did you ever replace it? My CEL came back on with the dreaded 0456 again.

 

thanks - that is helpful. once the CEL comes back on, i'll go about inspecting / replacing it.

 

I've had this problem for years. Took it to the shop. They did a pressure test. It was fine. They replaced the sensor. It's still saying I have an evap leak. It goes away by itself and then comes back. Very frustrating. If you figure it out, I would love to know how you did it.

 

Read post #21 about the scratch on the filler neck.

 

dupe

 

CEL came bacccckkkkkkkkkkkkkkk lol:

now i can test this latest piece of code for the CEL reply and then go about replacing that pump. hopefully it goes away for good..

 

@Fabio13 Amazing how sensitive these sensors are that a scratch would set it off.

 

just to update the thread - i replaced the evap leak detection pump (circled in red) last tuesday. since then i 've put a bit over 30 miles on it and the P0456 is still there.

given that its a permanent trouble code (since its related to emissions), i'm thinking that it might take some more drive cycles for it to go away.

i can fill the tank all the way up as well and see if that helps (i'm at about 3/4 tank).

if the code still doesn't go away, i'll go about inspecting some of the hoses and update as to what i find.

fun times

 

just to update the thread - i replaced the evap leak detection pump (circled in red) last tuesday. since then i 've put a bit over 30 miles on it and the P0456 is still there.

given that its a permanent trouble code (since its related to emissions), i'm thinking that it might take some more drive cycles for it to go away.

i can fill the tank all the way up as well and see if that helps (i'm at about 3/4 tank).

if the code still doesn't go away, i'll go about inspecting some of the hoses and update as to what i find.

fun times

Any updates? My 0456 came back again after being of for more than a month. Changed the gas cap, was fine for over a month, now CEL back on.

 

Hope you're not overfilling the gas tank. Should stop at the first click.
Nick in gas metal filler neck was my issue.

 

it always stops at the first click (9 years and running). i've never overfilled it.