what usually fails during a emission test? And what is normally replaced?

 

I dont think there is a "usual" fail. Do a full tune up, set timing, make sure cat is good and 02 are good. Tps set correctly.

 

yearly test is coming up think its not gonna pass... just want to know what should be fixed before i take my car in...

 

I would say a tune up for sure... you cant go wrong doing it anyway. If all your vacuum lines and sensors are hooked up correctly you should be fine. I had a 92 si that didn't pass and I did a tune up, o2 sensor, and cat and I passed with flying colors. Get the cat nice and hot before you go.