Check engine light - code showed "small evap leak"

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miles01

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My check engine light came on.
Fired up the ALFABDO, said small evap leak, cleared the code and all good.

What is a evap leak?
 

crash68

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It has to do with the gasoline vapor containment system. It could be a bad or loose fuel cap, a bad sensor, purge valve problem, etc.
 

carmantl

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My 17 3500 srw had same problem. New gas cap didn't fix it. Finally dealer had time to look into problem(after waiting 2 months to get a time slot). Smoke test sent them to top of tank. After dropping the 52 gallon tank, they found that "critters" had chewed through the plastic line that runs to front of truck for EVAP gasses return. I did not get to see the evidence, they had truck for a whole week, would not warranty repair cause of "critters". Cost me $430 and a week of lost wages. I make my living with that utility bed.
 

Ray Baumgarte

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My Check engine light has been on for several years, I had it to the dealer and smoke test did not reveal the problem area. They told me that I need to replace the fuel tank ($1000 plus labor) but would not guarantee that it would fix it.
for the past 3 smog cycles (every 2 years) I would clear the code by removing battery cable, drive the vehicle for about 40-50 miles and take it to the smog shop-passes every time.
I would like it fixed, but not a my expense of throwing parts at it.
I only have 242,000 miles on this rig-I bought it new.
 

Hemi395

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Get a new ESIM, they're like $20 and easy to put on. 90% of evap problems on these trucks have to do with the ESIM
 

wallacemf

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My 17 3500 srw had same problem. New gas cap didn't fix it. Finally dealer had time to look into problem(after waiting 2 months to get a time slot). Smoke test sent them to top of tank. After dropping the 52 gallon tank, they found that "critters" had chewed through the plastic line that runs to front of truck for EVAP gasses return. I did not get to see the evidence, they had truck for a whole week, would not warranty repair cause of "critters". Cost me $430 and a week of lost wages. I make my living with that utility bed.

I had the same problem twice. I cut out the chewed section, and spliced in some vacuum line. I also slipped on some braided stainless steel sheething. It’s been fine since then.
 

JerryETX

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Get a new ESIM, they're like $20 and easy to put on. 90% of evap problems on these trucks have to do with the ESIM
This was the issue with mine recently. Went by Auto Zone, they pulled the code and printed off the likely issue which was the ESIM and that solved it. Part was more like $50 where I'm at but still less than anyone would have charged to fix it. Took about 2 minutes to swap out and that's because I took my time. FYI if it is the ESIM it may take a few days for the check engine light to go off. Took my truck 2 days before it cleared after I replaced the ESIM.
 

PolarisCobra

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I had that code, problem was purge valve.

See this - https://www.samarins.com/glossary/purge-valve.html - for troubleshooting help. I found a helpful you tube video that suggested taking it off, trying to blow through it. You should not be able to.

I tried it, could blow through a bit. Bought a new one, it was easy to tell the difference. On my 2017 5.7 liter, it is right up front on top, easy to swap.
 

Ray Baumgarte

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I had my Ram at the dealer and they ruled out everything except something they said was attached to the top of the fuel tank, (part of the tank) the reason why they wanted to replace the tank. I didn't, because I don't have the confidence that they know what they are doing.
 

GlennRH

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My 17 3500 srw had same problem. New gas cap didn't fix it. Finally dealer had time to look into problem(after waiting 2 months to get a time slot). Smoke test sent them to top of tank. After dropping the 52 gallon tank, they found that "critters" had chewed through the plastic line that runs to front of truck for EVAP gasses return. I did not get to see the evidence, they had truck for a whole week, would not warranty repair cause of "critters". Cost me $430 and a week of lost wages. I make my living with that utility bed.
Same thing with my last van, a few days after I bought it new. Chewed up the venting tubing. Thing is the check engine light does not show a problem until several start and stop cycles take place else it would have been on during the drive home from the dealer.
 
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