can an emission leak cause a high idle?

[Blackout51]

Ive been dealing with a high idle on my 1998 4.0 sohc and cannot figure out the cause, I reset everything last night and while driving it today I got two codes, the code saying the iacv can't reduce the idle (I forget the code number) and the p0455 code, which is a gross evap emission leak, the cause of this code I believe is a bad fuel filler neck because when I fill the tank all the way up fuel shoots out from under the backside of the filler hole, like it drains out under the car not out of the fuel filler door, but my question is could this leak cause a high idle? and I know the high idle isn't because of a vacuum leak because I checked all of the hoses and im not getting a lean or rich code either

 

[koda2000]

short answer is yes. but it would have to be a vacuum leak allowing air to get into the engine at an unmonitored point (past the MAF sensor). the SOHC engine is also susceptible to vacuum leaks due to faulty intake manifold gasket/o-rings. a gross evaporation leak will allow air to enter the engine past the MAF, so it is probably due to your filler neck issue.