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Discussion Starter #1
I have been getting the P0456 code for small EVAP leak for about two years. I have paid to have several smoke tests (they found no leaks) and replaced every component in the EVAP system at least once except for one -- the fuel filler neck, running from the fuel inlet to the gas tank. I am guessing it has a small leak or two somewhere in the tube. I just ordered one from RockAuto, a non-OEM from Spectra (Mopar no longer makes an OEM one). Not cheap, about $300.

Has anyone on the forum installed one of these and maybe have some pointers? It looks straightforward except that I am not sure how to get my arms up the fender well. Looks like it will like installing an exhaust but the bolts will be way more difficult to reach? I assume that I should run the gas down to nearly empty before I attempt this?

Thanks for any help. Pray that it works. I would just ignore it but we have mandatory emissions testing in my state so I have to fix.
 

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I've been ignoring the P0456 for years. It comes and goes. But we don't have emissions tests.

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I live in the Northeast US. We have emission Nazis, and so testing is required every two years for any vehicle that is five or more years old (unless pre-1995). For the last test about two years ago, I was able to clear the code and then drive long enough through enough cycles to permit the emission testers to pass my Commander (but the first time that I tested, I hadn't waited long enough and so failed and paid a late fee). But now the light is coming on weekly, so I have to fix. I need to move to another state.
 

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I have been getting the P0456 code for small EVAP leak for about two years. I have paid to have several smoke tests (they found no leaks) and replaced every component in the EVAP system at least once except for one -- the fuel filler neck, running from the fuel inlet to the gas tank. I am guessing it has a small leak or two somewhere in the tube. I just ordered one from RockAuto, a non-OEM from Spectra (Mopar no longer makes an OEM one). Not cheap, about $300.

Has anyone on the forum installed one of these and maybe have some pointers? It looks straightforward except that I am not sure how to get my arms up the fender well. Looks like it will like installing an exhaust but the bolts will be way more difficult to reach? I assume that I should run the gas down to nearly empty before I attempt this?

Thanks for any help. Pray that it works. I would just ignore it but we have mandatory emissions testing in my state so I have to fix.
Recommend you look at the Fuel Pressure Sensor, which send info to the ECU. A bad Fuel Pressure Sensor will block all other EVAP components from working.
 

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I have been getting the P0456 code for small EVAP leak for about two years. I have paid to have several smoke tests (they found no leaks) and replaced every component in the EVAP system at least once except for one -- the fuel filler neck, running from the fuel inlet to the gas tank. I am guessing it has a small leak or two somewhere in the tube. I just ordered one from RockAuto, a non-OEM from Spectra (Mopar no longer makes an OEM one). Not cheap, about $300.

Has anyone on the forum installed one of these and maybe have some pointers? It looks straightforward except that I am not sure how to get my arms up the fender well. Looks like it will like installing an exhaust but the bolts will be way more difficult to reach? I assume that I should run the gas down to nearly empty before I attempt this?

Thanks for any help. Pray that it works. I would just ignore it but we have mandatory emissions testing in my state so I have to fix.
You have tried quite a few things thinking it is a valid code, but I had a very similar situation and it turned out to be caused by damaged wiring that started to corrode causing an intermittent code, but got worse and then a constant code. I have found damaged wiring below the battery tray and also in the area near the carbon canister for my 2006 4.7L. Problems found by checking continuity between sensors and wiring harness connectors. While this may not be your problem, it sounds like some of what I went through. Good luck.
 

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Discussion Starter #7
That is good advice . I will check wiring this weekend. That didn't occur to me.

Sent from my SM-T560NU using Tapatalk
 

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I've had the P0456 code for a while as well. Here's a similar post with some info. I have replaced the gas cap, vapor canister purge valve, charcoal canister and leak detection pump / ESIM. But the code still comes back. I'm thinking it's either some bad hoses, fuel tank or maybe the fuel filler neck. There arent too many other parts to replace!!
 

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Discussion Starter #10
I have also replaced all of the things you list. I am replacing the fuel filler neck this weekend.

I am going to check the fuel pressure sender and check the electric connections next, as suggested by other posters.

I have gone a few weeks and sometimes over one month without the code coming back in the past, so it can be difficult to know if the issue is fixed.

Good to have this forum to get advice from others.
 
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