Nope. It's a completely different engine management system. OBD I vs OBD II (on your car)
If you're looking for the extra HP that is lost tot he 323 the first and I mean FIRST place to start is the exaust. You've got a major bottleneck because the downpipes go into a single cat and all the way back via a 2.5" pipe (not sure on the size could be 2.25)
My vote is to get a custom set up that does either a 3" pipe all the way back, or the dual 2.25 inch pipe like on the other 6 cylinder 3 series. Then go for an m50 intake manifold and an OBD I conversion and you'll be set for 190 horse.
Kevin (President TBEA)
"WAAAAAAARRRRRIORS, come out to plaaaaay."