NZskyline wrote: Are the OBDII systems able to be installed in a car, and if so, would someone go to the trouble? Is it a costly proceedure? .
OBD II is a car wide system of emissions monitoring. It is a tip to tail system that uses a lot of sensors to figure out what is happening with the emissions that a vehicle is putting out. The OEM's had problems getting systems to work right in 1996. Most of their OEM systems were not fully functional until around 1999, although you see systems that are missing big chunks of parts until 2001.
The problem would be even once you get the system on the car and working, which we have already done in ~2003, then it all must work, and be tested in Ann Arbor Michigan in front of the EPA.
Once you start adding up costs, no one wants to do it. Just in parts, wiring, extra oxygen sensors, misfire detection, egr, smog pump, catalytic converters, tank pressurization sensors and wiring, ecu, programming, testing, you are about $7500 - $10,000 in a car, if everything goes perfect. Getting the system certified is about another $50k-$100k to realistically do it on the smallest budget possible.