Idle's high and smelling gas, whats wrong?

[dsm03]

So when i drive the car and its at normal operating temp. after awhile of driving it sometimes idles anywhere from 1800rpm-2200rpms. At one point it was going off the roof near like 3400rpm, I popped the hood and found that the coolant resevoir cap was opened so i closed it 30 sec later went back to normal idle speed. So i though ok shouldnt do it anymore but it still is. Also, i smell gas coming from the front it gets bad when i crack the window a bit and the smell is really strong. What could these problems be?? Theres no vacuum leaks and the fuel filter has just been changed. I was thinking it could be the tps but just incase im wrong. My brothers A4 1.8T had the same problem and it was his coolant temp sensor, do you guys think its the same thing??

 

[totaleclipse3]

Well the gas smell could be an exhaust leak. Also you might want to check the ISC as it has been known to cause idle problems. Hope this helps.

 

[TjPhillips36]

I would check and make sure the fittings around fuel filter are not leaking since you say it was just replaced. I would also test your ISC to make sure it is working properly.

 

[dsm03]

dumb question but how do i test the ISC, guess i have to get a computer scan?? my check engine is on and i have had it scanned. my mechanic clears it and it comes back keeps coming up as a o2 senor not sure which one but its the same one that hes cleared twice...were having trouble figuring it out

 

[TjPhillips36]

http://www.dsmtuners.com/forums/newbie-forum/273307-idle-speed-control.html#post151306992

 

[dsm03]

well i went ahead and purchased a coolant temp sensor hopefully it fixes the problem ill let you guys know how it turns out and if not ill replace the ISC thanks for the help