Yesterday I was driving with the cruise control and going up a small hill it downshifted kinda harsh and I took it off cruise and not long after the check engine light started flashing for 20 seconds or so and went out .Then about a couple hours later I was driving and tranny seems to upshift and down shift a little bit harder than it ever has and check engine light flashed for about another 20 seconds and went out Now I noticed that the AFM is stuck in V8 mode.What could go bad making it stuck in V 8 mode? Everything is stock , so I never did AFM delete. It has 144,000 miles on it and oil has been changed every 4000-5000 miles. What could cause it to stick in V8 mode? Thanks.