resisting acceleration and hard idle

[mrharmon10]

I did a search and i can't really find out exactly what i need to know. WHen i cut my car on it idles really wierd almost like a drag car. it idles really hard but when i drive it it runs fine until about 20 or 30 minutes then it starts to resist accelerating. It doesn't Bog i just resists, but it gets full boost. If i cut the car off it runs fine for a little while then starts to do it again. please help me out. it idles hard and resists acceleration. S13 sr20det(completely stock) in an s14 body(everything stock but exaust.)

[S13FASTBACKSR]

hmm thats wierd that it only does it after 20-30 minutes..easiest way to diagnose this would be to see if the ecu is throwing codes