CEL on and pulled codes P0455 and 2 x P0441
 

Durametric tool shows:

P0455 - Evap emission system leak - large leak
P0441 - Evaporative Emission System - Incorrect Purge Flow - Short to Ground or Positive
P0441 - Evaporative Emission System - Incorrect Purge Flow Present


From what I've read, EW had the 0441 with tank valve and Dennis had the 0455 with gas cap being loose (don't tell his wife).

Anybody seen this combination of faults and know the remedy-(ies)

What'd you do?

I suspect my wife left the gas cap loose after filling up on Sunday and that may be causing the 0455 code. The other two I'm not sure about. The car is under CPO warranty so it will go in Monday. I will post back with findings and solution.

I was posting so others can easily find it in the future. I would like a little guidance so I'm not going in blind to the dealer.

For grins, I tightened the gas cap and reset the codes with the Durametric tool. A few ignition cycles should tell me if the problem will re-surface....

Stopped for gas yesterday and had a really hard time re-starting the car. It cranked and cranked and finally fired up after applying some throttle through the pedal.

So far, it appears to be pointing to the tank valve issue that EW had.

Here's the verdict
 

Ok... Got the car back and the dealer pulled the code P0441 and diagnosed the Tank Vent Line P/N 948-110-202-01. This code re-surfaced after I cleared them on Friday to take care of the 0455 (gas cap).

The part lists for ~$90 and the shop charged 1.5 hrs for labor.

Below is the diagram for the part. It appears the vent is on the left end where P/N 20 and 30 plug into. It is electrically actuated. I'm guessing this may be a common failure as the cars get older. BTW, my 2005 CS has ~61k miles on it.