I know I am running rich as I have backfire at 4,500rmp+ when i left off throttle, even when under no load. I just got a bottle of new seafoam and going to put it in the tank (half of it anyways). New NGK O2 sensor can be had for $84 so I might get that, but today i rechecked and my egr and it doesn’t open at all under free revs, so it might be BPT or even EGR solenoid…