Bridgesm14

Hey guys, so I've been searching a ton and so far nothing so figured I'd make my own thread. Anyways, a little info on the truck, has a t3/t4 ball bearing turbo with the a high flow cat and a a brand new 3 wire heated o2 sensor in the downpipe. I've been driving it for about a year and half and it's always ran a little rich I think, on deceleration it would pop like a backfire but it ran great. Well the other day I was getting up to speed and was getting on it in second then shifted to 3rd and it just felt way off and ever since then it's been missing at low rpm. It will hesitate when just cruising along at steady speed and feel like a big gust of wind is pushing you. I put that new o2 sensor in because the computer was throwing a code for the old one but the truck runs the same. O checked the afm using a multi meter and it checked out okay. The truck still runs amazing after 3000 rpm when under high load so I'm kinda confused. I do have a exhaust leak pre o2 sensor that will be fixed soon so maybe oxygen is escaping or getting in causing a bad reading? I tried unplugging the egr vacuum lines buy nothing changed and when I put the paper clip in the diagnostic plug for the check engine light codes, the engine idle doesn't change. I heard when I put the paper clip in my engine idle should change right? I removed all the sparkplugs and they all seemed to be within specs. Any suggested on stuff to try will be appreciated

EDIT: Forgot to add during cold idle it idles good then when it warms up it will *POP* out of the exhaust about 1-3 times a second. Also around 1900 rpm when sitting in neutral revving it will backfire very rapidly, POP POP POP POP.