You can go for Akras if its about 500 bucks, which i think it is impossible.. a used stock exhaust from US set me back at less than 280sgd include shipping and if you are lucky, you can even find a cheaper one.. A certified pipe still will be stop by them cos they wanna check your cert.. and when you produced the cert.. they start to fault on other stuffs eg. signal, number plate and mirrors, thats if you not using so call legal wan la.. haizz..