2006 Liberty Sport 3.7 EVAP system nightmare. Seeking info, suggestions, help.

JeepSpace

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I'm not sure it works that way on the lib as the OP said his mechanic replaced a leak detection pump. Detection pumps provide plenum (or positive air pressure) to the system- as opposed to engine vacuum as in your scenario.

A look on the bottom side of the hood might provide a diagram of the EVAP system and show the presence- or lack of- a pump. The service manual would also show it: http://www.colorado4wheel.com/manuals/Jeep/KJ/
Yes pump was replaced, technically twice, once alone, and then again with pump filter ( not the canister though). Also, see above comment as I added some new info in response to Michael. I can afford a new cannister atm, and could probably get it installed this week, but I was still holding off a bit to see if I saw any other advice or suggestions. I don't want to spend more money guess and check testing, at the same time, if I got it, it would either fix the issue or rule it out as part of the problem.
 

Mangate

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Even though you have done a smoke test and visually checked everythng. I would still be tempted to replace some of the rubber pipes in the lines from the purge valve to the rear of the vehicle and those on the vapor cannister. The one causing problems on my 2002 is just inside the rocker panel on the driver side near the front, more or less under the driver seat. From memory I think there are two behind the engine and an elbow on the cannister that can cause problems. From the age of the vehicle they probably need changing anyway, yours are older then the age of mine when the started to perish and crack.
 

Jay Michigan

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I had the same issue on my '07 Liberty. If I just put the gas cap on normally - a couple of clicks and go - I'll get a check engine light and evap code. But I found that when I gas up if I cinch the cap tight, between clicks, so that there's absolutely no movement on the gas cap the check engine light will clear after a couple runs and stay off as long as the cap is tight.

All that said, I don't know if this might be causing too much vacuum in the system and cause a problem down the road.
 

runfor5

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I have fought a P0456 "Minor EVAP Leak" code on my 2004 Jeep for years now. It comes and goes lol. I have had a smoke test done twice, once on the overall vehicle and last fall, on just the fuel sending unit itself (see below). My initial issue was found upon dropping the fuel tank during the smoke test and testing it itself (total cost was about $600 bleh). I had a pin-hole sized leak in the fuel sending unit (?), the separate plastic assembly piece that sits at the top of the fuel tank and to which the fuel lines + EVAP lines attach. That part is no longer made by Chrysler nor aftermarket. So the shop plastic soldered the hole, CEL went off, and I passed emissions. That was about ~5 years ago. Emissions is due every 2 years where I live. Last time I passed the light randomly went off so I immediately ran and had it done. Was an idiot and did not do that this winter. Now my emissions test is due next month LOL.

I dropped the fuel tank myself last fall after having the CEL on all last year (and still today), took the fuel sending unit to them on its own, and was told no leaks found on it ($80). So I am assuming at this point it is something rubber somewhere.

Long story short, in your case, if you have tried everything else (which I did short of replacing the charcoal canister) ABSOLUTELY have the smoke test done and be sure they drop the fuel tank and test around those connections. Might get lucky.
 

JeepSpace

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Even though you have done a smoke test and visually checked everythng. I would still be tempted to replace some of the rubber pipes in the lines from the purge valve to the rear of the vehicle and those on the vapor cannister. The one causing problems on my 2002 is just inside the rocker panel on the driver side near the front, more or less under the driver seat. From memory I think there are two behind the engine and an elbow on the cannister that can cause problems. From the age of the vehicle they probably need changing anyway, yours are older then the age of mine when the started to perish and crack.
Thanks for the suggestions.
 

JeepSpace

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I had the same issue on my '07 Liberty. If I just put the gas cap on normally - a couple of clicks and go - I'll get a check engine light and evap code. But I found that when I gas up if I cinch the cap tight, between clicks, so that there's absolutely no movement on the gas cap the check engine light will clear after a couple runs and stay off as long as the cap is tight.

All that said, I don't know if this might be causing too much vacuum in the system and cause a problem down the road.
I will explore that a bit. Though I did think I was getting a problem or different results with the 3 caps I have, at this point it does it with any of the caps, so it's likely either the gas neck sleeve (if it's related to the gas port at all) or something else still all together.
 

JeepSpace

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I have fought a P0456 "Minor EVAP Leak" code on my 2004 Jeep for years now. It comes and goes lol. I have had a smoke test done twice, once on the overall vehicle and last fall, on just the fuel sending unit itself (see below). My initial issue was found upon dropping the fuel tank during the smoke test and testing it itself (total cost was about $600 bleh). I had a pin-hole sized leak in the fuel sending unit (?), the separate plastic assembly piece that sits at the top of the fuel tank and to which the fuel lines + EVAP lines attach. That part is no longer made by Chrysler nor aftermarket. So the shop plastic soldered the hole, CEL went off, and I passed emissions. That was about ~5 years ago. Emissions is due every 2 years where I live. Last time I passed the light randomly went off so I immediately ran and had it done. Was an idiot and did not do that this winter. Now my emissions test is due next month LOL.

I dropped the fuel tank myself last fall after having the CEL on all last year (and still today), took the fuel sending unit to them on its own, and was told no leaks found on it ($80). So I am assuming at this point it is something rubber somewhere.

Long story short, in your case, if you have tried everything else (which I did short of replacing the charcoal canister) ABSOLUTELY have the smoke test done and be sure they drop the fuel tank and test around those connections. Might get lucky.
Hey thanks for the ideas, first time I'm hearing them.
 

JeepSpace

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For those following the thread, or others who come across it using it for research, I haven't been able to do any updates over the last 2-3 weeks. However, I just acquired an Evap Canister, and am replacing it on Sunday, 5 days from now as my next attempt. I will update the thread with the results next week.

Also, to all those who have contributed to the thread so far, thanks.
 

ddranch04

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For those following the thread, or others who come across it using it for research, I haven't been able to do any updates over the last 2-3 weeks. However, I just acquired an Evap Canister, and am replacing it on Sunday, 5 days from now as my next attempt. I will update the thread with the results next week.

Also, to all those who have contributed to the thread so far, thanks.
I had similar issues with my 2007 Liberty in 2018. Evap codes, GASCAP code, new gas cap, smoke test, etc. Nothing fixed it or could be
found. Broke down and went to dealer. They diagnosed ESIM Switch(some youtube vids on this). Replaced ESIM for $88 and havent had the problem since.
 

adamkrz

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With my 04 I had a po456 that I could not be located w/ smoke or visual inspection, wasted money by changing parts -canister - and every other part in the evap. system, finally dropped the fuel tank and found the plastic bushing on top of the tank had small cracks causing the small evap leak code, part was not available so I sourced from a junk yard, I know the 06 is different then a 04 as far as the tank goes but who knows..
 

JeepSpace

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I had similar issues with my 2007 Liberty in 2018. Evap codes, GASCAP code, new gas cap, smoke test, etc. Nothing fixed it or could be
found. Broke down and went to dealer. They diagnosed ESIM Switch(some youtube vids on this). Replaced ESIM for $88 and havent had the problem since.
Thanks, good one to keep in mind, first time hearing of it.
 

JeepSpace

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With my 04 I had a po456 that I could not be located w/ smoke or visual inspection, wasted money by changing parts -canister - and every other part in the evap. system, finally dropped the fuel tank and found the plastic bushing on top of the tank had small cracks causing the small evap leak code, part was not available so I sourced from a junk yard, I know the 06 is different then a 04 as far as the tank goes but who knows..
Thanks. Yeah, I'm running out of parts of the Evap system itself to check or replace. If this canister doesn't fix it, idk, everything else is leading to a problem with tank, sleeve, or fuel system itself. Just learned of another suggestion, ESIM, from above poster too. Will know more on Sunday.
 

runfor5

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With my 04 I had a po456 that I could not be located w/ smoke or visual inspection, wasted money by changing parts -canister - and every other part in the evap. system, finally dropped the fuel tank and found the plastic bushing on top of the tank had small cracks causing the small evap leak code, part was not available so I sourced from a junk yard, I know the 06 is different then a 04 as far as the tank goes but who knows..
What do you mean by “plastic bushing”? See my issue posted about above which I refer to that entire upper assembly as the fuel sending unit (that’s where my crack was). I ask because my code is still on and tags expired last month, emissions passing required to update registration where I live LOL.
 

adamkrz

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It's the plastic under the lock ring that had tiny cracks - The 04 was 2 pieces and it was the top housing that had cracks- not sure of other years,
 

JeepSpace

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Still no luck :( :(

So this is an update as of June 12th. I replaced the EVAP canister on June 2nd. The GASCAP light came back on less than 1 hour after the repair. The Check Engine light stayed off for a few days, but then reappeared and has been on since, as well as GASCAP light. The 2 biggest symptoms I'm noticing are A) still a regular smell of gas fumes which I'm fairly sure are coming from the rear of the vehicle, and B) then engine "chokes out" when starting after I've run it for a long time and then stop for gas or to make a delivery, turn it off, and then go to start it again. However, if I cycle the key and let the gas pump build pressure before trying to start it, it starts fine. It always starts on the 2nd or 3rd attempt, and it doesn't always choke out, actually mostly it doesn't, but that's what happens when it does. So, fumes and intermittent trouble starting that is resolved by turning key in stages.

I'm still throwing codes. P0457 - Loose Fuel Cap, P0456 - System small leak, and P0440 - General EVAP system failure.

Another poster suggested the ESIM, but from what I can tell I don't have that piece ??? couldn't find it for my year, will also respond to that post directly.
Other suggestions are still Fuel Neck Sleeve or Fuel sending plastic pieces?

I ordered yet a 3rd gas cap to try and will report back after it arrives. At this point, I'm going to have to break down and go to dealer and pay a ton if I can't figure it out. Maybe get another smoke test, ? idk. I want that gas smell gone so badly :(

I'm also posting a recap of the original post and updating it, so people don't have to look back.
  1. Noticed the vehicle would choke out and have trouble starting after driving a few hours and then stopping to fill up for gas. Vehicle would choke out while starting, but if I tried a 2nd time it would start. Soon after, it started with the Check Engine light and an EVAP code. Came back "Small Evap Leak" code.
  2. Mechanic A suggests it could be Purge Solenoid, Evap Canister, or Gas Cap. Suggests I should start with the Cap as it's the cheapest test and fix. Replace OEM Cap from dealer. Problem persists.
  3. Replaced Purge Solenoid by battery. Problem persists.
  4. Reset Codes. Codes and check engine light come and go. See GASCAP light intermittently now comes and goes.
  5. Mechanic B runs codes and gets "Large Evap Leak." Suggests it could be Evap Leak Detection Pump, Evap Canister, or leaks in lines, connections, hoses. Suggests doing Smoke Vapor Evap test first to check for leaks before buying more parts. He also suggested that if I cycled the key when I had trouble starting, to build pressure in pump/system, and then started, that it should help. This was confirmed. Every time I had trouble starting, if I cycled key once first, listened for gas pump to fire and build pressure in the system, and then tried to start it, it would start right up and not choke out.
  6. Do Smoke Leak Test and physically inspect all outer components of system. Results find no leaks at all. Mechanic B suggests it could still be something internal to Leak Detection Pump or Evap Canister, and to start with the Pump since it is the cheaper fix. He also suggests it could be Gas Pump, but doesn't think that's the issue or I would be seeing other symptoms.
  7. Mechanic A replaces Evap Leak Detection Pump. Problem persists. Mechanic A suggests that sometimes it's still a bad gas caps and to try another.
  8. Replace Cap with an after market cap. Problem persists.
  9. At this point, I'm still getting random Small Leak and Large Leak codes as well as the GASCAP code, and I am also smelling fumes every once and a while when I'm towing and accelerating hard to keep up speed while going up steep hills. The fumes usually go away after 15-30 minutes and or when the load calms down. Both the codes, check engine, GASCAP, and fumes all come and go. Sometimes it's a week or 2 with no issues or symptoms, and then they will just pop up again. Then it can go another week or so with no codes or issues; so very intermittent. The GASCAP light has become more regular, almost constant now.
  10. Take it to Mechanic C to see what he can find. Mechanic C says it's likely the Evap Leak Detection Pump Filter, but that because I didn't replace the Pump and Filter at same time, that the new Pump could be ruined. Suggests I replace Filter and now Pump again, making sure to do the filter first. He also suggests it could be the Fuel Pump or the Gas Tank Sleeve, but that the sleeve should have showed up in the Smoke test.
  11. Replace Evap Leak Detection Pump Filter and then the Pump again..... Problem persists.
  12. UPDATED : Replaced EVAP Canister - still didn't fix it, still getting P0457, P0456, P0440, and GASCAP lights - Trying a 3rd gas cap, will report back.
 

JeepSpace

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I had similar issues with my 2007 Liberty in 2018. Evap codes, GASCAP code, new gas cap, smoke test, etc. Nothing fixed it or could be
found. Broke down and went to dealer. They diagnosed ESIM Switch(some youtube vids on this). Replaced ESIM for $88 and havent had the problem since.
From what I can tell, I don't have a separate ESIM? Could be wrong though. Looks like it was on certain years, but not the 06?
 

DadOSix

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From what I can tell, I don't have a separate ESIM? Could be wrong though. Looks like it was on certain years, but not the 06?
From my reading - ESIM and evap leak pump are 1 and the same.

white part on the back of the canister under kj
 

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