i just installed my new dc jdm 4-1 header with a testpipe I had bought off a guy that had it on the same header, but on an SI. I also bought the donut gasket fromt the s2000. When I tried to bolt them together the opening was the same size and even with the donut gasket. It bolted uo but Is this the way it shoud be? Anyone have pics? Also I took it for a drive and seems like the vtec doesnt kick in as strong. Is this also normal? One more thing. When I get on it and let of the gas, I hear a vibration. I can hear it in the car but I can not hear it outside.

Thanks a lot,

Bonnie

 

The test pipe/cat isn't going to completely cover the donut gasket if that's what you're asking. As for the vibration, check to make sure all your bolts are in the header and cat and that all your bolts are torqued to spec. Many people get exhaust leaks and vibration by not torquing the bolts high enough. You'll need a torque wrench to get it to the proper rating.

 

I have found that test pipes and aftermarket cats all have some sort of rattle. It is milder on some but especially on deceleratoion it is noticable.