Ive had this problem off and on for a few weeks, since I put on my wai and 58mm tb; sometimes it will go away but then it will come back. I get a check engine light and trac off, and when I let off the gas my rpms will drop back to normal then bounce to like 1500-2000 a few times. I changed my IAT and IAC sensors, but could this be my tps or a vac leak somewhere? I read the code and its p0507

Has anyone else had this problem?

I would worry about a vacuum leak or bad seal on your new TB, may want to check your torque there.