Emissions warning light on holden astra

[MudwiG]

Car is a 2001 Holden Astra 1.8

The emmisons warning light is now constantly on the car, before I take it to the garage to get checked over does anyone have any ideas, as to what the problem might be, and what the damage might be $$$ wise?

Also can anyone recommened a good garage in Sydney, ideally the Eastern suburbs?

Thanks in advance

[Burnedout]

Most likely the Cat Converter issue.
Just take it to any GM Dealer.