I have a b16a1 in a CRX with a 8 lb flywheel ( stock cams), the normal bolt on crap, intake cold air box, dc sports header and a very low back pressure exhaust system. the car is an auto x car and with a 4.40 final drive it gets out quick.. I ported a type r intake and installed a isolator gasket to keep down the temp on the intake and now have a 5 k dead spot. The car has good power up to 45-4700 rpm then falls off until 6k or so then you just have to hang on for dear life until the rev kicks in. Any ideas??? I was going to start with cam timing but figured it would not hurt to ask here first..

 

If you can dyno it w/ afr do it soon and I almost can say with 100% accuracy that it is a fuel related problem, if its not then may I ask you if you have changed the vtec setting w/ some sort of aftermarket ecu, if so vtec may be too high, way too high. Or on the other hand it could be some sort of oddball mechanical failure. Search around and fix everyting that possibly could be wrong until its cured and your car should run like a champ.