Code P0442 for 1999 Pontiac Grand Am 3.4 V6

I have been fighting a P0442 code (Evap Emission Control System, Small Leak Detected) for several weeks without success. There are no other codes.
So far I have:
-replaced gas cap
-checked vent solenoid. normally open, when energized with 12v closes completely.
-checked purge solenoid. normally closed, when energized with 12v opens.
-visually inspected canister (did not remove it for inspection) and it looked OK, no cracks
-visually inspected hoses going into canister and purge valve for damage, none found
-found vapor hose from fuel tank to canister was loose at canister. built up canister fitting with tape to get a tighter fit.
-visually looked for fuel leaks and none were found (no gasoline odor under car either)
I did not do the following:
-probe wiring harness to verify PCM is actually controlling the vent solenoid and purge solenoid (there is 12v at purge solenoid harness)
-drop fuel tank to inspect hoses going into fuel pump
-inspect tank and fuel fill pipe for leaks
-check fuel pressure regulator for leaking diaphragm
-check fuel tank pressure sensor
-check all hoses and tubing for leaks
I am at a loss as to what to do next. I do not have access to a lift or test equipment to pressurize the system to look for leaks. I jack up the car and crawl under it to work.
can anyone give me a list of most likely to least likely items to check for a leak?
after fixing, how many driving cycles are needed to turn off the "service engine soon" lamp?
Haynes and Chilton manuals are vague as to which codes on their list of possible codes apply to which cars. For example, on this car, will I see a P1665 or P1675 if the vent solenoid control circuit is bad or a P1655 or P1676 if the purge valve solenoid control circuit is bad. Or does the PCM not check those functions on this car? Can someone tell me what PCM codes I can expect from this car? And, more importantly, what the PCM does not check?
Any help would be greatly appreciated.
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