Vauxhall Tigra cant get egr valve off

they could be torx bolts they might be t30 or t40 not to sure if they look like stars they are torx bolts hope this helps

Hi Antony-I had the same prob. as you; I got around it by using an Allen key[correct size!] as follows: remove top manifold etc. then insert the long end of the Allen key into the bolt-use a torch to see what you are doing, having first put a small sleeve over the short end of the Allen key; I also tied a lenght of string to the key[in order to be able to retrieve the key if dropped!]; you can now turn the bolt;
Finally, hacksaw the the rear lug before replacing Egr valve-it makes it much easier to replace!