Just installed a dc sports jdm 4-1 header/car sound cat. on a 2000 integra gs-r yesterday and I've noticed that the shifter seems to feel a little ruffer I think the linkage is hitting the car sound cat. I've noticed that when I let the rpms fall to idle the shifter shakes.

 

Does anyone even have the jdm dc sports 4-1 header/car sound cat. ?!

 

look underneath the car to see if the linkage is touching the exhaust, it should clear just fine because the linkage sits high and usually -- stock they have a guard. that shouldn't affect your shifting though. the bolt that bolts the linkage to your shifter might be too tight or not lubed enough for the bearings to move around. Check those as well. Also make sure your shift linkage to the tranny is secure.

 

with a skunk2 shifter an an apexi n1 catback my shifter just taps/rattles the resonator when in 1st, 3rd and 5th gear.

so I bent the hangar posts on the chassis under the shifter area to lower the exhaust a half inch or less, perfect solution. no ratles either. if you set it up like this be sure to check your muffler tip I had to adjust mine because it was almost touching the bumper.
good luck bro.

 

Ok thanks for the suggestions. I checked a few hours ago and the linkage is really close to the o2 sensor on the cat. I think it's rubbing slightly.