2003 chevy tahoe 5.3L Flex Fuel 2WD EVAP (P0446)

2003 chevy tahoe 5.3L Flex Fuel 2WD EVAP (P0446)
Unfortunately, I have changed all the evap parts except for the canister, No pellets coming out It also breathes. Replaced gas cap, fuel tank, pressure sensor, purge valve & vent valve. I've had tech say there was a short in the electrical plug common to the vent valve, I may have misunderstood but I did change out the electrical plug that goes to the vent valve. Been working this issue for months, little bit at a time in most instances. Light would come on usually the second or third day drive. Battery has never been that strong after purchasing the vehicle three or four months ago, So replaced with very good battery. So after replacing with new battery the Light went off by itself About two weeks later.I thought it was the battery. I thought it fixed the problem but, it come back on. So that's where I'm at, Would love some help on this. I have a test light and a multimeter, Have scan tool but not bidirectual. 
 

if you did all that you will have to get a smoke machine, they have cheap ones on amazon

Without a proper smoke machine and a bidirectional scan tool, I wouldn't be able to fix a P0446.

It may be more cost effective to bring it to a repair shop than to buy these tools if you aren't planning on fixing cars every day.