Yes, you can game online with pirated games on an Xbox.But, you have to be a little careful when updating because the updates might kill the mod.Ask the CD shop if you can update the game before updating it.
Also, let me tell you that Xbox Live isn't free like PSN,you have to buy a membership card. The Xbox Live Gold 3 Months Subscription [US/EU] costs 23$ and as for 12 Months Subscription [US/EU] $54.00 @
PC and Parts