Bad clunk no first or reverse
2005 LLY 160k stock trans
So I was full throttle on the highway getting a little rowdy and when I let off there was a big thud and the check engine like came on. I still seem to have full power no limp mode and nothing else on the dash besides the check engine light. I don’t have reverse and it seems like either first is slipping really bad or the truck is trying to start off in second gear. It’s also holding gears out pretty long. Is it something small/fixable or built trans time?