07 Tahoe LTZ - EVAP Emissions Question

[mljohns4]

Looking for some feedback on what my next step should be. I have been throwing code P0442 about every 3 weeks for about the last 4 months. So far I have sequentially replaced the following components

OEM Gas Cap
EVAP Canister Vent Solenoid Valve
EVAP Ccanister Purge Solenoid Valve
EVAP Vapor Canister

All my hose connections seem to be tight and clean. I have once again set a check engine light with P0442. I have used the search forum search function but I haven't found anything that mimics my scenario. In most folks cases one of the four items above resolved their issue. Question is do I take it into a shop capable of performing the smoke test or is there another component that could cause the issue which I haven't covered yet. Any thoughts on items I should examine that is not covered on the list above? I should mention that either ACDelco or GM parts were used for all replacements.

I do not have any other codes being thrown and I also do not have the characteristic hard to fill gas tank either. I have the computer based ScanXL software I can use to interface with the vehicle if there is something I should be paying attention to there as well.

Thanks
Mike

[j cAT]

this is because you have a small leak. could be the vapor lines but I have seen the filler neck rust threw where it has a weld to support it . I used some metal mender to seal those holes ,,, PIN holes.. you may indeed have to get the smoke test . post where the leak was . this forum works only when members support it by posting the repair. so far 2007 tahoe with this code is not common now but could be a fleet wide failure.