Toyota Repair: code p0442, smog test, carbon canister

Question
I have been for 3 months now getting check engine light with code 0442 on es300 lexus 2002 with 120000 miles on it i made sure gas cap tight, changed gas cap with new toyota one, changed carbon canister and the light keeps reaperaring please help.

Answer
The 442 code is a very small leak in the evap system, it could be a cracked hose on the system or a bad connection at one of the hose's 0-rings or a leak at the fuel filler tube, this type of leak is difficult to locate, the evap system should be pressure tested or tested by injecting smoke with a special machine, the smoke will exit into the air and can then be located, most dealers or smog test stations have this machine, this would be the most reliable way to find the leak instead of just putting more parts on that may or may not fix this leak.