dragonxbreath

So i have a single apexi rx6 turbo and my exhaust warning light is coming on right around 800C. The other night it came on and my turbo warning light came on right around 6200rpm and caused my engine to stall for a sec, possibly cut the fuel. Can anyone tell me why it's not letting me hit full boost at higher speeds b/c of this warning. Possibly a tuning issue, maybe air/fuel ratio is off. My engine temps are solid however, never reach over 92C. Any help would definitely greatly be appreciated. Oh and the exhaust outlet for my turbo is being dumped next to the cat, could this be causing the overheat as well?