the potential problem is that the flanges of the hks and the stock exhaust are different styles. The stock system uses a donught style gasket which means that one side is dished in and the other out so they fit inside each other. The hks has a flat flange. The problem is that the two different styles don't match up all that great and they are more likley to leak. Now most people have been able to bolt them up with little problems now does that mean they don't leak no maybe they do a little and they just don't notice it. They are made to bolt up to the HKS cat back and yes it does go with the apex because they are made by the same company. My view on the subject is this it's $150 so if you don't want to spen a lot of money then it's probably worth a shot because it will probably be ok. But on the other hand it's $150 and like they say you get what you pay for.... which in this case is a plain no bells or whistles DP that will probably give you a HP gain. which is what it's all about right?

 

ive had mine for a while now. the only problems that i had was that it was loose and that was b/c of the person that had installed it. but that was corrected later. no problems w/ fitment

frederick

 

No problems with my HKS dp and N1.