I have to go for an emissions test in March and I'm wondering if I just swap in the stock h-pipe will I pass or no? Are there any fluids or gimmicks I can buy at the auto store to ensure that I will pass?
As long as you have the stock H-Pipe on and a decent set of mufflers you should pass. Unless there is something wrong with the car that is preventing it from passing.
You may want to kick your timing back down as well, but really you don't have a whole lot of mods, so you should be fine without it as long as you throw the stock hpipe on.