It was midfielder Johnson who brought PNE level from the penalty spot in the 61st minute of the clash at the Select Car Leasing Stadium.
The Royals had taken the lead through Femi Azeez, a graduate of their Under-23s side, in the first half.
Just eight minutes after DJ coolly converted from the spot, Reading regained the advantage through John Swift.
A late rally in which they forced home goalkeeper Rafael Cabral into two good saves, failed to get North End back on level pegging.
Johnson said: “When you equalise away from home naturally you want to push on and try to score a winner.
“What you sometimes have to do first is get the game to the tempo you want to play it at.
“If that means slowing it down a bit at free-kicks, goalkicks, throw-ins, so to get the crowd on their backs, you have to do it.
“Then you can pick things up again and see where that takes you.
“What happened was that Reading scoring the second goal swung it back to them, they had the momentum.
“We should never have conceded the second goal after getting ourselves back into the game.
“It was a poor goal for us to concede, both goals were sloppy from us.
“We chased the game after their second goal and we did create some good chances.
“Their keeper did well from Brad Potts, from one of my shots which went through a crowd of bodies and from Ben Whiteman’s free-kick.”
Johnson felt parts of the game PNE did well in, others not so.
The main statistic though, was that North End remain pointless after two games.
Jamaica international Johnson said: “There were a few positives.
“We create0d more chances than we did in the first game against Hull.
“Our focus is on what we do this season, not what we might have done last season.
“ That has gone now and we have to look ahead.”
Johnson’s penalty, given for Reading defender Michael Morrison handling a shot from Alan Browne, got the midfielder off the mark for the season.
He scored three times from the spot last season but did miss from 12 yards in last year’s visit to Reading.
The 28-year-old went for pace on his penalty, that beating the dive Raefel who went the right way.
Said Johnson: “You have to be confident taking a penalty, stay calm and try to block out all the noise going on – you have to have tunnel vision.”
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