Now usually Ive got my music pumpin when I drive, so if theres any small sounds my car makes Im not gonna hear it. However today was a different day. On the way home I was hearin this rattling sound, from either the exhaust or close to engine. I thought it may be low oil, since Im always leakin, and threw some in. The sound was still there.

It makes this rattlin sound below 2500 rpm aor when you let push the clutch in and rpms drop. So the closer I get home the more I notice the car bogging. Like pressing the gas and now power. The engine trys to work harder and I get a deeper tone, but no more speed. Back pressure prob feelin, ya know. So Im thinkin the cat is **** on, but Im not throwin a cel and wired in a new O2 within the last couple years. What do you guys think?? I dont have a backup car and have to be at school tomorrow for a final. Im may just pull it in the garage and bust a hole through the cat...

 

okay pulled in garage, massive rattle from exhaust/catalytic area. Guess Ill be havin a high flow cat in the next few mins.

 

its not your cat, its an exhaust leak somewhere, if its bogging real bad, its probably before the o2 sensor

 

cracked header?

 

i had the same problem a couple months ago, since the guy that installed my custom exhaust didnt know how to weld for ****. Anyway the problem was when he put in the exhaust pipe from the turbo DP, the DP was 3.25 inches in diameter, but he only had 3" piping. So i just told him, weld a reducer to the inside of the DP and the exhaust..so anyway he welded the smaller segment of pipe in there and it worked fine.
Until, however, I competed in a solo autox. After a few good solid shifts the welds snapped, and this rattle started, if i dropped rpms below 1500 it would rattle, or around 3600-3900rpm it would rattle pretty bad. It was the reducer pipe inside the dp rattling around from the welds being snapped..so anyway i just went to the muffler shop, paid another guy 20 dollars to reweld the **** and now its all good and done.

 

nah, it was the cat. All I have to say is that if I didnt have air tools I wouldve got real pissed. I just punched it out and now I can actually feel vtec hittin again. So what really makes a cat go bad? aside from a bad o2 sensor? Cuz mine aint old and I wasnt thrown any codes.

 

it maybe could have overheated and clogged itself up.

 

placebo