The cost of inspection = FREE
All you need to do is book in, arrange time off from work, buy permit for unrego'ed car in NSW and ACT on said day (if needed) and drive up.
I failed my first one and passed the second, all cause I didn’t swap the hi-flow cat (real, not gutted) for the standard.
The difference was;
Hi-flow = THC g/km 2.74, NOx g/km 4.08, CO g/km 10.3 and CO2 g/km 230.0
Standard = THC g/km 1.88, NOx g/km 2.17, CO g/km 8.2 and CO2 g/km 221.3
one way to pass is to use a standard exhaust and mod it to have 2 catalytic converters, or use a smaller than standard cat.
Basically just keep the volume of gas down.
Hope this helps
Now, where's that jelly bean...