Macclesfield must wait if they are to add to their recent list of FA Cup scalps after Oxford somehow escaped from Moss Rose with a 0-0 draw.
The National League side created plenty of chances against their League One opponents but could not find a winner in front of the TV cameras, having dumped Walsall out in the first round.
Simon Eastwood saved well when defender Chey Dunkley's tackle deflected the ball goalwards on 24 minutes, before Paul Lewis twice missed the target after finding space.
Jack Mackreth then sliced wide from a tight angle on 39 minutes with team-mates screaming for a cross in the middle, while right-back Andy Halls shot over from distance five minutes later.
Oxford changed formation in the second half, though, and Dunkley headed just wide from Chris Maguire's free-kick midway through the half before Craig Ross saved from Tyler Roberts on 71 minutes.
At the other end, Eastwood showed great reflexes to keep Lewis' low shot out on 76 minutes before Mackreth went even closer four minutes later when his right-footed shot cannoned off the post.
Neither side was able to break the deadlock, however, and the two teams must meet again in Oxford to decide who reaches the third round.