Boost creep in 3rd gear..

[Cakes]

From a dead stop I get o2s around 800 with 0.0 knock but from a roll at around 55 matted in 3rd gear around 78 mph I have the same o2 readings but 3.3 degrees of knock and I noticed my boost hit 17 and then crept (sp?) to around 20. Any idea of what I can do to fix this problem? Thanks for your time!

 

[turbot2112]

i see you have the stock exhaust elbow, does it have the stock puck on it. if so you may need a bigger one. check to see if the puck is covering the wastegate hole. take the elbow off and smear some atv silicone on it, then bolt it back on and smack the flapper arm a couple times and take the elbow back off and you should see if the outline of the puck is covering the hole. goodluck