Question about a Type R i'm considering buying and emisions

[BLaDz01]

Hello all. I went and checked out a 2001 Black type R today. It is some what modified and, while this would usually dissuade me from buying the car, the seller is a friend of a friend so I trust him. Two modifications he has done could have implications for passing emision tests. The first is that his exhaust doesn't have a catalytic converter. The second is that the CPU was replaced with the JDM ODB2A(is this the correct part number?). He doesn't know if the car will pass emisions. He said i could put the stock exhaust back on to fix the problem with the catalytic converter. He also said I could get a used stock CPU from possibly a GSR which would run me around $200. He said that it is easy to swap them. Anyone have any knowledge about this? I need to decide if I want it within a few days because another buyer is coming to pick it up. This is currently the only thing holding me back from getting it.