Doesn't appear to be the issue with mine, but taped that area with gorilla tape for a little extra strength anyway. I'll go back under the tank at some point to do more inspecting.

 

that white "C" shape clip that is above the blue electrical connection in post #20... I broke mine in the past due to the brittleness of it and just used a zip tie to the front end keep the connection secure and have never had an issue since..
just extra info to help you solve your issue.

 

Just thought I'd update this. I was up for inspection so reluctantly I had to bring it in. They replaced the Purge Solenoid (which was the VERY FIRST THING I replaced initially based on the info from here) which resolved the issue. So infuriating. I even did the blow test and it seemed to be fine. Sigh....guess I'm just glad it's over with

 

Purge (under hood) or Vent (behind gas tank)? If the Purge valve it was probably the connection to the valve not the valve itself. A bad Purge valve usually presents as a air/fuel mix problem.

 

I have been dealing (or not) with P0442 “Evaporative Emissions (EVAP) System Small Leak Detected” and notice that the connectors too the purge valve (under the hood) seemed loose. Thinking what seen to be o-rings inside the connectors may have shrunk, I applied a tiny bit of grease. Went from returning the cleared code in a week to taking about 4 weeks. Are those replaceable o-rings in there? That purge valve was replaced a few years ago with the one from AutoZone that looked identical to the OEM but I wonder if maybe the fittings are undersized. Gumming up the connectors with some kind of sealant doesn’t seem like the best idea.

 

I’ve experienced new valve , still codes, replaced valve codes gone, first valve from Amazon, second from RockAuto, both AC Delco .

 

Something you need to keep in mind is the system can get contaminated with charcoal even if the canister is dry. They can fail internally. Best to blow out the purge line and if there is charcoal in there the canister needs replacing,