Stumbles at high rpm then loops

[Shane@DBPerformance]

If you have to go positive on the hi-throttle map, then you are possibly going to run into fuel cut. You shouldn't really ever have to go much positive on a DSM, unless something else is wrong or your MAS is really hacked or you are trying to run a 2G MAS with stock 450cc injectors in a 1G.

If you are running a stock 1G MAS, you might be hitting MAS overrun.