pre 96 imports should be tested at basic idle test. You will need to get emmissons below 3.5% co2. Should fly thru if the cars mapped via ecu or piggy back. If it's just an fpr you may have to turn down fuel pressure a little bit but probably not.
Not
quite right.
Pre 01 Aug '95 cars where the engine code cannot be identified do not require a basic cat test. They fall under the category of a basic emissions test, which as you correctly stated, is ~3.5% Co2 at idle. Post 01 Aug '95 cars where the engine code cannot be identified (ie, late GT's and all
Glanza's) are required to pass the basic cat test. This test has a limit of ~0.5% for idle and ~0.3% for fast idle.
Check your V5 and pray the "approximate date of first use" is Pre 01 Aug '95. If it is, don't worry about it. If it isn't, you better put your cat back on and pray she passes.