Another aussie..!
You can change to a smaller engine (which would be the second cheapest way), but the easiest and cheapest way is to just sell the 626 and buy something with a smaller engine.
If it has to be 4 doors, look at Toyota Corollas otherwise get a Starlet ($1500) like me.
If I had my time again, I would have tried to find a 'Lean-burn Civic' though I'm not sure these made it to Australia
You can destroke that 2.2L to whatever you want, except the cost would be ridiculously stupid and then the cylinder head ports would be too big for the reduced capacity, thereby reducing volumetric efficiency and then the cam timing would no longer be optimal either, the list goes on and on....
Putting it bluntly, get a different car.
