Toyota Repair: P0441 and P0446 Fault Codes, toyota dealer, gas cap

Question
Ted, My '98 Corolla CE (75000 miles, 1.8L engine, mauual transmission) has been displaying the check engine light for approx 6 months, and comes up with the 2 fault codes above (it shows the P0446 code twice).  When the fault is cleared, it comes back in about a week of driving.  When I checked the gas cap yesterday, I noticed a strong odor of fuel when the cap was removed (much more than my other 2 vehicles).  Does this condition point to a specific part being faulty?  If not, what do you recommend to check to eliminate these faults?  

Answer
These codes are emission control related and indicate a leak in the fuel evaporative system, this is a complicated system and requires technicians that really know what they are doing to diagnose.
If you want to try a simple repair yourself replace the gas cap with a OEM unit from the toyota dealer, that's about all I can recommend, if that doesn't help it's time to get some help from real professionals that can diagnose this kind of problem, there is a battery of tests that must be performed to isolate this problem, my best advice is to get the toyota dealer involved.