Knocking (Pretty sure not retard) after SLP exhaust install

Ok, 04 GP, put on Thrasher cold air intake, no prob, but after installing my SLP exhaust, I get a knocking/clicking noise at 40% throttle and under, RPM & gear don't matter. If I give more throttle it goes away, but under that certain throttle/load I guess it knocks/ticks.... Not sure how to discribe, any ideas?

Thanks

did you put headers on or just the catback?

Just the cat back

did you use a new gasket at the flange next to the rear o2 sensor?

Yea, it came with one, and I used it

this is a known issue, check how close the filter is on your intake to anything. I bet it's tapping against something under that acceleration. Best test I did was take off the filter (just for around the block) to see if the noise stops it did for me. I then ripped it off and put on something more potent in it's place

cool, I'll give that try, thanks