97targa

The plates move freely and the cable lines look alomst new, so what could be the problem? Engine has 53kmi on it and burns no oil, runs great. Could be better on top end with those plates open, although I guess they are prob. better off being stuck closed than stuck open...lol Could there be servo issue or would the computer pick that up as a code? I tries some seafoam through the pcv valve, but didn't do much, not even smoke out tailpipe? They will move with me doing it manually though. Any ideas?