Hello.

I currently have two codes for my 2004 Quest, P0455 (Evaporative Emission System Leak (Gross Leak/No Flow)) and P0447 (Evaporative Emission System Vent Control Circuit Open).

All signs are pointing to the EVAP (Vapor) Canister and/or Vent Control Valve. These two items appear to quite easy to replace based on what I am reading. Unfortunately, I am having a hard time finding them on my Quest to inspect them.

Has someone replaced these parts in the past or can someone point me to the location? I believe they are in the rear of the vehicle but would like to get a general idea before jacking it up, removing tires, etc.

Thanks in advance for your help.

According to the online service manual it is located in the rear crossmember area. Here is a link for the manual. Go to Quest and select year.

http://www.nicoclub.com/FSM/quest/2004_Quest/

http://www.nicoclub.com/FSM/quest/2004_Quest/ec.pdf

Thank you for the information. I do appreciate the assistance. The issue ended up being a bad Engine Control Module (ECM) that rusted out and was water penetrated. I would have much rather had it be the EVAP Canister.

Again, thank you for your help.