On my eco lately I've been having a bit of an idle issue. It happens randomly, some days it won't do it at all, some days it does it all the time. When I down shift to come to a stop, I can feel the car wanting to "accelerate" at about 1500 rpm. It won't delecerate all the way down to about 900 rpm (normal idle). So when i come to a stop and push the clutch in, the car idles at about 1500 rpm. It doesn't jump around or anything, it just sits there. It will sit there until i tap the gas, then it will just drop down to it's normal idle. I've noticed it doing this after I fried my cat just before xmas. At the same time i got the cat replaced (not an oem cat) I also had my EVAP done as it was throwing a code because of the vent solenoid. Is this my TPS? I don't think I have a vac leak cuz my boost/vac gauge still reads normal at idle. Any ideas?


  

I dont know what causes that but every once and while when I start mine it will idle high for a few minutes then drop down to where it normaly sits.

sticking throttle plate when you tap the the gas it gives it enough force to slap shut all the way. just a thought i have torn a few T/Bs apart and every once an while the plate will get in the bore just a hair off causing a vacuum leak.

with symptoms like yours.