that dreaded P0455 code has everyone stumped!!! 2004 aveo

I purchased a 2004 aveo from a friend 2-ish years ago, ran good, no c.e.l. replaced the cracked windshield, new tires, interior a/c control panel & a few other little things. drove it maybe 10 months until the c.e.l. came on (P0451). replaced the gas cap and pressure sensor (on top of the gas tank) and it went away. now the P0455 code has triggered, EVAPORATIVE EMMISIONS SYSTEM LEAK DETECTED (GROSS LEAK / NO FLOW) the c.e.l. and ive been stumped, my mechanic friends are stumped & a friend who owns a show hooked up various machines / laptop & even he is stumped, no clue. I can reset the c.e.l. and within 5-10 miles its back.
I have tried to search this site for other people who have shared this delima but its not the easiest site to "cruise" through various threads........................

IM JUST LOOKING FOR IDEAS / OPTIONS / SOLUTIONS as I have had a non-op on it for over a year now.

Here is the most recent tread on the same subject. Might be some info here you can use.

https://www.aveoforum.com/forum/f81/...55-code-23748/

maybe the voltage drop on the stock part was 'too close to the code' after plugging and re-plugging in the code still appears from time to time hilarious.. maybe have to find another to test more