The draw stretches Wanderers' unbeaten run to four matches ahead of a trip to Hartlepool United at the weekend.
Gareth Ainsworth made two changes from the side that drew with Blackpool at the weekend with Dominic Gape and Weston coming in for Sam Wood and Paris Cowan-Hall.
After a fairly even opening, Adebayo Akinfenwa almost gave the Chairboys the lead with a spectacular effort on 8 minutes. The target man held his ground before twisting and hitting a shot on the half-volley from 30-yards, which had McCormick beaten all ends up but just whistled past the far post.
A few minutes later, the hosts went close again as Weston latched on to a ball looped to the back post. The winger hooked it back to Luke O'Nien who then took aim, only to be denied by McCormick.
Michael Harriman tried his luck from on the quarter-hour mark, though the Argyle stopper was equal to the effort low to his left.
The chairboys were peppering the Plymouth box with dangerous balls, causing confusion amongst the Plymouth back line, and they took full advantage as Weston, back in the side, hit home after Harriman found him at the back post from the right on 18'.
That was the midfielder's second goal for the club, the first of which came in the reverse fixture on Boxing Day at Home Park.
That goal galvanised Wanderers, and they looked to double the lead. Weston whipped in a free kick from the left which Aaron Pierre headed back across goal and just over the bar with 30 minutes played.
Argyle came back, and produced their first clear-cut chance of the game on 34' as Matty Kennedy jinked into the box before shooting goalwards. Blackman was equal to the effort before Jake Jervis' rebound was deflected over.
With less than five to play in the first period, Wanderers almost made it two as Weston curled a ball into the area from the left. The ball was met by Akinfenwa who connected with his thigh but saw his effort bounce wide.
Half time: Wycombe 1-0 Plymouth Argyle
With both sides coming out for the second period looking for that elusive second goal in the game, it was the home team who came closest on 53 minutes. Weston floated one in after gaining a yard on his man and met the head of Gape. The midfielder nodded it down towards goal but McCormick was there to deny him.
Wycombe's first change of the game came on 54 minutes as Cowan-Hall replaced Dayle Southwell. The creative attacker was straight into the action and zipped in a wicked cross which Akinfenwa couldn't quite convert.
Up the other end, Argyle were attempting to crank up the pressure. Graham Carey fired in a splitting free kick from just outside the area which luckily evaded any Plymouth oncoming attackers as the keeper and the defence were carved apart.
Argyle had their equaliser on 73 minutes. Blissett, who had just come on as a sub for Antoni Sarcevic, headed home a corner moments after Blackman had denied him with a superb save.
Max Muller was replaced by Will De Havilland at the back on 75' as Wanderers looked to regain their advantage. They nearly did, but for a smart save from McCormick as Cowan-Hall found his fellow substitute with a low ball. The defender flicked it neatly towards the net, but the Plymouth stopper got down well to his right to keep it level.
Looking to pull a winner out of the bag, Ainsworth's final switch came with four minutes to play as Sam Saunders replaced Weston. Given that Wycombe had made all their subs, many panicked when Marcus Bean went to the floor injured, luckily he was able to carry on.
Jordan Slew replaced Jimmy Spencer for the visitors as both sides went in search of a priceless winner. Wanderers had to be on their metal to scramble away a late Plymouth corner. They did and that was the final action of the game as the points were shared at Adams Park.
Attendance: 3,538 (652 visitors)
£1 Draw - £467: 36305
£2 Draw - £73: 48151