Tubbs, a half-time replacement for Lee Barnard, headed home a Lewis Grabban cross in the 74th minute to cancel out Greg Tansey’s first-half opener for the visitors.
And a string of fine saves from Arnold, including a wondrous last-gasp stop from Grabban, ensured Stevenage would leave with a point their heroic defensive efforts merited.
Boss Howe had the luxury of being able to name an unchanged starting line-up as Cherries went in search of a fifth league win in succession.
Fifth-placed Stevenage arrived at Goldsands Stadium looking to bounce back after suffering consecutive 4-1 defeats at the hands of Preston and Sheffield United.
Visiting defender Bondz N’Gala’s tame header was saved comfortably by Cherries goalkeeper David James before Marc Pugh’s driven free-kick cannoned off a defender and sailed over the crossbar.
Cherries created a glorious chance following a 13th-minute short corner, only for Barnard to see his effort from point-blank range saved by Boro goalkeeper Arnold.
Arnold again distinguished himself when he dived full length to his left to claw away Grabban’s header, the striker meeting a Charlie Daniels cross in the 26th minute.
Cherries were rocked just a minute later when Stevenage opened the scoring though Tansey, the former Inverness Caledonian Thistle man’s ferocious strike giving James no chance.
Tansey converted via the underside of the crossbar from just inside the 18-yard box after good work from Marcus Haber down the right flank had created the opportunity.
Barnard was thwarted by a series of blocks, the Southampton loan man continuing to try his luck from range before a Daniels volley was snaffled by Arnold on the stroke of half-time.
A switch at the break saw Tubbs replace Barnard, the Verwood-raised striker tasked with helping Cherries overturn their interval deficit.
Shaun MacDonald clashed heads with Stevenage defender David Gray as he climbed to nod a cross from Simon Francis narrowly off target.
Grabban went close to levelling when he arrived at the far post to meet Pugh’s hanging cross, the striker, who was stretching, lifting his effort over the crossbar.
Daniels slalomed his way into the 18-yard box, only to poke his shot wide of the upright, before Grabban blazed into the crowd when a cross seemed a better option.
Tubbs was Johnny on the spot to equalise for Cherries, the substitute showing all his predatory instincts to nod home Grabban’s precision centre from inside the six-yard box after 74 minutes, amid furious offside protests from the visitors.
Miles Addison wasted a gilt-edged opportunity to put Cherries in front when he headed wide with the goal at his mercy from a Daniels cross 11 minutes from time.
And as chances came thick and fast for Cherries, Grabban was also errant when he skied a shot into the North Stand after Pugh’s low cross had found him 12 yards out.
As Cherries poured forward in the closing stages, Arnold pawed Addison’s header around the post before Grabban fired straight at James Dunne who was positioned on the line.
Stevenage went close to snatching a late winner with James saving low down after Robbie Rogers had let fly from 25 yards.
Former Eastleigh goalkeeper Arnold saved his best until last, his top-drawer block keeping out Grabban’s fierce drive deep into injury-time.
Cherries: James 7, Francis 7, Addison 7, Elphick 7, Daniels 7.5, McQuoid 6.5 (Fletcher, 84), MacDonald 7.5, Arter 7.5, Pugh 7.5, Barnard 6.5 (Tubbs, h-t, 7), Grabban 7.
Unused subs: Cook, Fogden, O’Kane, McDermott, Jalal (g/k).
Stevenage: Arnold, Gray, Roberts, N’Gala, Charles, Akins, Dunne, Grant, Hills (Rogers, 67), Tansey (Shroot, 82), Haber (Agyemang, 72).
Unused subs: Iro, Comminges, Risser, Day (g/k).
Booked: Akins, Gray.
Attendance: 5,504 (including 136 visiting supporters).
Referee: Tim Robinson (Sussex).