[grazi]

Mine was doing basically the same exact thing as yours. I threw alot of parts at it. It ended up being that the cat was clogged. I seen yours is high flow but maybe do like I did. Shoot the front side with an IR thermometer and compare it to the back. There shouldnt be much difference in temp. I did mine and it was around 300 degrees difference . I gutted it and mine runs like a charm now for about a month.