How long does sauce last?

One year may be pushing it.  Really depends on the PH of the sauce.  If there is no acid in it, you should keep in the refrigerator after making and only for a couple of weeks at most.  If you acidify it (vinegar, citrus juice, etc.) to at or below 4.6 (I think, others can correct me if I've used the wrong number), it should keep for 6 months or so at room temperature.  Note that also depends on the bottling method.  You should have made sure the bottles and all cooking utensils are sterile, and when bottling the sauce you should have also made sure that the bottle sealed properly.
 
 If you've not done so already, and/or are not already familiar with best practices, read up on this topic for proper ways to do all of what I mentioned above.

I am currently enjoying one of my superhot sauces made almost 2 years ago - the last bottle of several cases. It was made with plenty vinegar and believe the pH was tested below 4. I don't sell anything (yet) but give lots away. I always date the label and tell people to toss it after a year to be safe.
 
Properly bottled stuff with low pH should last 2+ years, but it's always best to err on the side of caution. I hear botulism is no fun.

Well I made a very runny sauce with unripe peppers,put about 3 table spoons of vinager in,made a 300ml jar and put it in the refrigerator,when I opened it yesterday the lid made a popping sound

what kind of "popping noise"? 
 
When heated sauce is put into a jar and the lid is applied, when it cools it will create a vacuum.  So even though you may not have done a boiling water bath, it's likely the jar created a vacuum that "popped" when opened.  Even a room temp sauce put into the jar and refrigerated will create a vacuum because of the temp differences.
 
On the other hand....if it was a PFFFT kind of sound....which is what happens when something spoils and off-gasses building up pressure in the jar.  Often times chile products will do a type of fermentation when they spoil, and not the good kind of fermentation for making sauces. 
 
 
3Tbsp vinegar in about 1.5 cups of sauce is a little light, but considering it's been refrigerated, and if the POP was from breaking a vaccum on the lid, I'd go for safe.
 
Beyond this example, sauces can be good for 3 days (with no acidity in them) to infinity and beyond for things like Tabasco, Tapatio, and other sauces with really low pH..... the color may deteriorate over time, but the product should be safe to eat.