so a while ago i sold my complete turbo back exhaust, no cat on the DP. I had a Perrin divorced DP with HKS hi-power. Well recently Rmac gave me his catted helix DP with greddy catback. The car bucks at 5k. Its gotta be the catted DP throw everything off.... what do you guys think?

Funny because i remove the negative on the battery drive it, pulls hard then after a few runs it bucks at 5k

If it is infact the cat, does anyone wanna buy a helix DP? possible the full exhaust so i can buy something that will work!!