Went to clean the TB todayon the SSEI, and it'* stamped Hitachi. Did Hitachi ever make TBs for Series I or II for GM?

Every SI TB I've seen says Hitachi. I don't know about S2.

Yep, even mine says hitachi. I think its just the MAF housing tho.

both my 98 and 00 TB'* are hitachi

Mea culpa. Needless concern. I only saw it in one post here, and it was regarding a Vin C.

I have been having minor boost issues since I jumped up the intake. Thought there might be some issues re the sensors and cfm flow, if Hitachi was aftermarket.

as are mine

And if you look closely, Bosch makes many parts on the car as well.

including o2 sensor?

Let'* not get ridiculous, squirrel boy. NGK and Denso spark plugs are made in the same factory. I expect O2'* are also, and we suspect NGK makes the AC Delco O2'* as well as the plugs which are confirmed.

I think it'* safe to say we all have Hitachi TB'*. Every one I've had come through ZM has been as well, so let'* not turn this topic into a 'me too' for 37 pages.