I've been getting a P0450 code and a CEL usually a few miles after a cold start. Luckily I have a Scan Gauge and just reset the CEL. It doesn't seem to affect performance or mileage but I
really would like to get rid of it. The code translates to a pressure sensor fault in the emission system. Talking to the dealer, I found out there is a emission pump/sensor assy on the rear driver side beneath the fuel door. Looking under there for cracked hoses I found what seems to be a vent/filter assy next to the filler tube ahead and inside the rear fender. The assy looks disintegrated (vapors?) and its' hose goes down to the emission pump assy and seems to contain some kind of filter. I was wondering if anyone knows what this was and could it be causing the pressure sensor fault (maybe a one way valve in the assy). Anyone with any knowledge on the emission system of this car, inputs would be welcome.

 

If the system is loosing pressure then yes it could be throwing the code from the leak.