Bad Catalytic Converter?
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Pole Position
Joined: Jul 2007
Posts: 247
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From: CA
Bad Catalytic Converter?
I have a 1992 sc300 with 95,000 i have lost lots of torque and i hear a weird sound( sounds like air restriction) from under my gear shifter when accelerating. when i turn the car off i hear that new exhaust tick from under the car. Is there a way i can check for a bad CAT or should i run it to a muffler shop and have then check?
Thread Starter
Pole Position
Joined: Jul 2007
Posts: 247
Likes: 0
From: CA
the torque problem doesnt go away but it get worse and then randomly get better aswell as the sound coming from under the car. but at low rpms(1000-3000) the car runs fine and sounds fine.
what kind of gas are you using? you should be using 93. also check the air filter.
an exhaust shop can tell you if your cat is dead. it is usually pretty unlikely for a car with 95k to have a bad CAT. If you did emissions lately and your car passed its probably not your cat.
you could have a crack or something in the exhaust.
are you sure it doesnt make the noise during Wide open throttle from about 3500rpm-6000rpm
kind of like a whistle??
and if you let off the gas some or are not WOT it goes away?
cause that noise has to do with something else. (intake related)
an exhaust shop can tell you if your cat is dead. it is usually pretty unlikely for a car with 95k to have a bad CAT. If you did emissions lately and your car passed its probably not your cat.
you could have a crack or something in the exhaust.
are you sure it doesnt make the noise during Wide open throttle from about 3500rpm-6000rpm
kind of like a whistle??
and if you let off the gas some or are not WOT it goes away?
cause that noise has to do with something else. (intake related)
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it sounds similar to a really bad case of the intake whistle perhaps.
try searching for that.
I would really have to hear it to tell.
best solution and good maintanence anyways would be a thorough throttle body/upper intake manifold cleaning. it can get gunked up and at WOT when the IACV opens back up (under WOT only), it can make noises if there is carbon buildup (behind the throttle plate).
usually this sound comes from the engine bay though.
i think there is some kind of exhaust pressure test you can do to see if there is a restriction in your exhaust. get something flat you dont care about and use it to block the exhaust. you should feel a decent amount of pressure and your idle should change. if it doesnt there may be a restriction.
theres probably a better test. someone can chime in here.
try searching for that.
I would really have to hear it to tell.
best solution and good maintanence anyways would be a thorough throttle body/upper intake manifold cleaning. it can get gunked up and at WOT when the IACV opens back up (under WOT only), it can make noises if there is carbon buildup (behind the throttle plate).
usually this sound comes from the engine bay though.
i think there is some kind of exhaust pressure test you can do to see if there is a restriction in your exhaust. get something flat you dont care about and use it to block the exhaust. you should feel a decent amount of pressure and your idle should change. if it doesnt there may be a restriction.
theres probably a better test. someone can chime in here.
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Driver School Candidate
Joined: Feb 2008
Posts: 19
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From: VA
If the cat is clogged, the pressure could be forcing the exhaust apart, and make a leak in the exhaust, which could be the noise you are hearing. Get under there and unbolt the cat from the front part of the exhaust, and drive around a bit, through the neighborhood or whereever, if the sluggishness goes away, you have a clog.
Or you could go to a muffler shop, and they can test it for you.
Good luck
Dan
Or you could go to a muffler shop, and they can test it for you.
Good luck
Dan
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