H22a swapped in.. few questions

Well i successfully swapped the jdm h22a into my 92 si. Well, first off, it went in fine, started, then i went to drive it and it drove, but at random times it would just like putter out and bog down big time. then go to running fine, then bog down again, (prolly like 5-8 times throughout the rpm range). Well, as i drove it more and more, and got the vtec to work, it started to calm down more and more. Now it would only happen when it was under high stress, like trying to start off in second, or when it was at about 5000rpm+ (i realize it would still bog down, but this was obvious to me not normal). I was told it could be a vacuum line collapsing.. well i figured it would check it out, and as time went by it slowly went away til it was gone... now all thats left that seems to bug me is that at about 2-3k rpm ish it would seem a little sluggish, not near as serious as b4 but it would still bog down a little, i read somewhere that it could be the knock sensor. Has anyone else had this problem b4, could it be that knock sensor, or the O2 sensor, or maybe even the fuel filter or something. Well im just checking to see if anyones got any opinions... oh yeah.... VTEC is amazing. :grinno: