City, held 1-1 by Doncaster on their last Carrow Road outing, were presented with an excellent chance to take the lead in the 72nd minute when Darren Carter was penalised for handball.
But Hoolahan tried to chip the ball past Turner, who gratefully clutched the ball.
Substitute Chris Brown, who had only been on the pitch two minutes, handed Preston a surprise lead on the hour when he chested down a Keith Treacy pass before volleying past City stopper John Ruddy - his first goal for over a year.
But their lead was shortlived as Norwich responded within two minutes with captain Grant Holt tapping home his 16th goal of the season after North End keeper Iain Turner had parried Andrew Surman's shot.
The Canaries pushed for a late winner, which they have achieved many times this season, but North End held firm.
Norwich made a dominant start and Hoolahan almost gave them the lead in the eighth minute but his 25-yard shot went inches wide of the upright after fine play from David Fox and Andrew Crofts.
The home side continued to control the game and Fox then tried an ambitious effort from 35 yards which wasn't too far away.
Preston, without a win in 13 games in all competitions, survived the early onslaught and looked threatening on the break.
Canadian Iain Hume, restored to the starting line-up, blazed high and wide before David Gray drilled a shot from 30 yards which was comfortably dealt with by Ruddy.
Back came Norwich, though, and after a quick attack the ball fell to on-loan midfielder Henri Lansbury but his scuffed close-range effort was kept out by Turner.
Fox then struck a shot with his weaker left foot which drifted wide of the post as Norwich searched for the opening goal.
The second half sparked into life on the hour mark when Brown fired North End ahead with a fantastic finish against his former club.
But Norwich responded immediately with Holt grabbing his fourth goal in six games after great work from Surman.
Holt had another chance five minutes later but Turner kept out his header from Crofts' cross
Hume then clipped the top of the crossbar with a cross-cum-shot before Norwich wasted a glorious chance to take the lead when Hoolahan's nonchalant spot-kick was kept out by Turner.
Moments later Hoolahan nearly made amends but his 12-yard drive was tipped around the post by Turner, who then foiled Lansbury as City upped the ante.
With 13 minutes late, North End came close to taking the lead for the second time but Ruddy did brilliantly to deny Sean St Ledger from point-blank range.
Substitutes Aaron Wilbraham and Simeon Jackson were denied in injury-time as North End held on for a precious point.