ND-89-YOTA

Hey guys, im new to the site and looking forward to using it. But anyways, i just finished some exhaust work on my 89 pickup, 22re (i do have a cold air intake). I left everything stock from the exhaust manifold to the cat but directly after the cat i extended the diameter to 2in and then put on a a short glasspack and turned it out the side before the drivers rear tire. I didnt have access to a welder so i clamped the seams and used exhaust wrap and dont have any leaks as far as i can tell. Now when i drive at low speeds (forward and reverse) i hear a fairly noticable rattle which i think is coming out of the exhaust. It occurs when accelerating and decelerating (braking or just slowing), with the clutch in and out, and when im idling or giving it some gas. So basically all the time when im moving slow. Once I hit around 10mph the sound seems to go away and i cant hear it any other time although i dont know if it is actually gone or not, but the rattle sure seems to stop and start suddenly. I never heard it before with the stock exhaust but that was really quiet compared to this. So any ideas on what the sound is or what the problem is? Thanks.