The only prob I have had was the upper heat got a little loose and started rattling, just went back to the muffler shop and they tig weld it back down(in more than one spot hehehehehe to make sure) Other than that it has been great, but we'll see how good it is come inspection time in October. My friend has one on his B20/VTEC and he was able to pass emmissions so we'll see what happens.