whats the difference
 

whats the difference between a test pipe and a Y pipe?

Test pipes replace the catalytic converters with a straight pipe.

The Y pipe is the section of the exhaust that connects the test pipes (or cats) to the back half of the exhaust.

which one is better Y pipe cost more by like 60 bucks.... i dont know much about the difference in them or anything so just wondering

The test pipes/cats are loated in front of the y pipe example disregard the red circles
http://farm7.static.flickr.com/6239/...eaa1b8dc_b.jpg

test pipes will give a slight bump in hp because they free up flow by not having cats there. y pipe wont really do much with the stock back half of your exhaust on