My OBD2 reader and what they will use can tell if the codes have been recently reset. You will get a failure if you reset the codes prior to the test. This includes disconnecting the battery to reset the codes. In fact, if you have no codes and hit reset codes or disconnect the battery before the test you will fail. The monitored systems will show as incomplete in all the above cases. It takes some time for the monitored systems to show complete, and BTW if there were codes they will likely be back as well.
Cars 87 and older still do not need a test. This was originally cars older than 19 years and this date rolled forward as time went on. In 2007 (or was it 06) they anchored the date. If you have an 88 it will always need to be tested, if you have an 87 or older you are off the hook.
If your car is not OBD2 (I think 96 and older) they will be doing the old tailpipe test on it with the old equipment. If it is OBD2 then you get the new test.
E-tests are good for one year. If you have an even number year car you will have to get a test to get your 2014 plate. Assuming your birthday is not the last days of December if you get the test now it will be good when you have to do your plate renewal, a test now will be under the old system. Important if your CEL is on right now.... Or if you have an older car that may have some failure in the near future...
Some solid info. Thanks.