Okay, so I have a p0742 code. Basically the converter is up shifting to early and down shifting to late. I had a fluid and filter change done by a tranny shop and there was some filings but not to bad. Needless to say the problem still exists. Now when I drive I shift manually and was wondering the following things. If I properly shift manually will the tranny last forever? If I get a tranny from a yard does it have to be special because of the SC and sport shift button feature? Any other advice or recommendations?

Thanks, Jack

Could be a bad solenoid or a stuck valve. If you choose to swap transmissions you need to make sure it'* a 4t65e-HD If you get a 4t65e the diff is a bit smaller and the axle wont fit right.

Do you also have a P1811?

No P1811 and it is definitely the valve. Should I bother running some seafoam and can I shift manually forever?

You can shift manually, but it'* not fixing the problem. If the valve is stuck or sticking, seafoam can work it loose. But it can also cause a transmission that is on it'* way out to finally die all together.