I have been throwing p0441 and p0446 for months. I tried the gas cap replacement and just recently had both VSV's off the car and they checked out according to the diagnostics. The last choice was to R&R the canister. Before doing that I checked my vacuum hoses one more time. The EVAP hose from the EVAP VSV to the p-port on the TBI was split at the throttle body and brittle. The good folks at the delaership appear, from the way it was taped and such, to have known this when they rebuilt it for the sludge stuff a year ago but just put it back on without a real second thought. It took a few months for the electrical tape fix to wear out and then I started throwing the codes and getting the CEL/MIL. They diagnosed it as a bad can and I was ready to replace it with a used one myself. It was only by luck that I figured out that $1.50 in vacuum tubing was the fix as opposed to a $600 dealer canister replacement or a couple hundred in a pair of DIY VSV replacements and a used can. MIL has been off for three days and a couple hundred miles. And the idle it a lot smoother as well...