rd

hi guys I have a 97 xx, I just installed a unique exhaust from the italian company called teramignoni, looks great sounds good too, 4-2-1 with a ti can, I had a shudder before the exhaust, at around 5000 rpm at that point i only had vance & hines slip-ons, and a dynojet kit with a K&N filter now with the new exhaust the shudder is still there just not as pronounced, any idea's?