lately my car is making a rattling sound from the exhaust I pin pointed it down to the resonator. around 1-1.5k rpms it rattles and thats it, the thing is the car feels a lot slower now. I had the same problem a year ago with my 2.5" cat. converter going out. but now it's not the cat making noise it's the resonator. the car revs fine in neutral but in gear when I hit vtec the car makes a hideous sound and doesn't have much power. and it's not the deap whaahh sound you'd normally get it's a really loud nnneeeeeh type sound when you hit vtec. it sounds like the exhaust could be really restricted but I'm not sure. Has anyone had this problem and could it be a bad resonator. BTW the car is a 2000 Civic Si W/ Intake/ JDM4-1 Header/2.5" Cat(catsco I believe)/ Apexi WS Cat back exhaust. and the cat has been replaced with in the year..

Thanks in advance,
Justin

 

sounds like the deadning material in the resonator has taken a ****....you should remove the whole system and do a quick inspection

 

wel I got a check engine light and the code is 0420 catalyst system below threshhold. If my cat died again it's getting punched out.

 

either pop out that cat, or if you want to get rid of that check light, get an o2 sim

try and get a casper's electronic one

 

Take down the exhaust and have a look. Either the convertor has come apart or the resonator. Sounds like something is clearly blocking the exhaust path.