Originally Posted by josephbet01
There's an electric pump that pressure tests the system for leaks whenever the car "wakes up". You may hear it cycle quickly when you open the door first thing in the morning.
I believe I posted a pic of this pump at one point. It's located inside the passenger side rear wheel well under the plastic shield. Its called a DTML Pump. Worth about $100 and takes about an hour start to finish. Easy job.
If its not a loose gas cap this would be my bet.
Thank you, but do you think that this would send an emissions code?