ok so after about 3 or 4 months of having my intake on my car its a trick flow track heat with a one inch spacer and a 75mm bbk throttle body.... so any ways. i am driving around check engine light is going on and off but thats just my egr code coming up dont know why its going on and then off agian like every 5 or 10 mins. but what ever so if i am just slowing going up to like 4 grand to like 4500 rpms then it will start surging not to bad but like it has a miss or something. then if i am all out pedal to the floor once i hit 4k it will go lean no matter what and will stay there till i am off the throttle i dont under stand it this just started to happen. it has to be a fuel problem i mean becuse if i was not getting enough spark it would be to rich and my coil is new and i have new spark plugs and i have a new fuel filter in it to. so any info guys and that would be awesome i can post up a vid of the air/fuel ratio guage if you like to see what it looks like at full throttle and part throttle if it would help you know. thanks guys.