1996 Subaru Legacy No power

Were you having this problem before you worked on it? If not, then I would double check the timing.

Otherwise, Have you changed the filters, lately, air filter--fuel filter? Make sure no pressure on fuel system before replacing filter. Also, use a gage and check fuel pressure. Check applicable trouble codes.

I bought it with the timing belt was broke but I was told it ran good before that I did change all filters because it sat for a year. put all new gas in it timing marks are on I even counted the teeth between cogs ant it is correct. It idels perfect starts right up too could it be oxgen sensor or knock sensor engine light is on but whenit starts to spit and sputter engine light blinks

No offense, but, you bought a vehicle that wouldn't run? Check for applicable trouble codes, then we can dig into it. I'll have to look to see if this is an interference engine?