2005 chevy silverado 4.8L evap issue

[Ryland]

I've had my 05 Silverado for approximately 3 years now and I've been dealing with the evap code p0442 (small leak) for about 6-8months now. I bought the truck with 65k miles and its currently at 120k miles and I've kept up with all the regular maintenance I've tried the simple solutions such as changing the gas cap and replacing the purge solenoid. Neither of these solutions were able to solve the issue. I took the truck to a local shop who ran tests on the evap system, replaced both the purge and vent solenoid and smoked the system and reported back no issues. I ran the truck for about 3 weeks after this and the evap code came back so I took it to the same shop and they said nothing looks to be wrong with the evap system but suggested that the onboard computer needed to be replaced (I felt this was excessive). I then reset the code drove the truck. The check engine light continued to come on approximately 3-4 times before I then decided to try another local shop to see if they could find the problem with the evap system. They were able to run tests on the evap system for approximately a week and reported back that they found no issues with the evap system and reset the code. I've since had the check engine light come back on reading the same code. I'm curious if anyone has seen this issue before. I feel as though I've exhausted all possible solutions on fixing this issue besides throwing more money at it. Thanks for any feedback!

 

TLDR: Evap code p0442 continues to pop up after multiple shops have tested evap system with reports that its fine

Edited August 25, 2021 by Ryland

[txab]

Here's a little info on the evap system

 

https://www.gm-trucks.com/forums/topic/104569-the-evap-system/