I managed to find the source of my 'sputter', two small hole in my exhaust just after the O2 sensor.

Can this be fixed without welding ?

 

I'd try hi temp JB weld. It should do the trick, and if it does burn off, its not like it would be hard to re-apply.

 

Welding is the best option.

 

Welding is the best option, but if you do not have the ability to weld yourself then take it to a local muffler shop, these pin holes can cause more problems than you think. As long as the pipe isn't corroded and you have enough meat left on the bone then a decent shop should be able to weld for cheap. I would not recommend JB weld or a exhaust repair kit.