2002 Oldsmobile Alero intake manifold upgrade

I'd need to know which engine you have. But I don't suspect there's much available for you motor.

And are you sure you want a high-performance "intake manifold", or do you mean "Cold Air-intake"???

Upgrading an intake manifold by itself will do absolutely nothing, and may even hurt performance. (The MAF, injectors, exhaust and computer programming would have to be changed as well in order to work as a system)