Them chips are for the 16vt not the 20vt
they are no good on idle during cold starts, i had one on my 16vt and the it made it alot quicker but engine not quite as smooth as the gtrchs are on the 20vt.
Dontno if anyone else has menioned it but it requires the cold plugs and to be safe a session on the rollers to make sure the fueling is right.