This is question is related to high potential gum in gasoline ex FCC. We have 2 gasoline merox reactors (A&B) and recently we have bypassed 1 reactor(A). Thereafter we observed some abnormal results of high potential gum (as high as 1300 ppm). On further analysis, we have checked merox inlet (B) and outlet(B) as well as combined outlet(A&B) i.e., Rundown. we have found high gum at inlet (1200 ppm) and immediate out let (500 ppm) and combined outlet (900). As per literature and my experience gasoline merox reactor doesn't contribute or treat potential gum but couldn't able to find the source. Also inlet is higher side, we have checked olefins at inlet (28% reported). what could be possible reasons for high gum at inlet and why are we observing gum abnormalities across reactor?