I have a 2006 Kia Rio base model that has been having fuel/emission system problems. So far I have replaced the CCV and the FTPS. Currently the vehicle will start, but typically after a few tries, but will only remain running if I keep the RPMs above 1000. For the most part, once the RPMs drop below that, the car will die. After driving it for a bit yesterday, I did get it to idle once I got back home, but it was very very rough. While sitting there seeing if it would die, I heard a fan like noise and when tracking it down, it appeared to be coming from the gas tank and I could hear the bubbling of the gas above the sound of the car idling. I dont ever remember this happening before. Currently I show a p0452 and p0132 code. Ive gone through the steps for testing for p0452 (minus the part using the vacuum gauge) and ended up just replacing the FTPS. Which at this point means, I either have an open in the ground in the electrical system or I need a new ECM. I also have noticed that if I pop off the fuel cap while the vehicle is running a huge burst of air can be heard (not sure if its pressure or vacuum). And at times when turning off the vehicle, a whining sound can be heard coming through the fuel cap. I was thinking about replacing this and see if any symptoms stop. Any other ideas?