Do I need a new catalytic converter?? - Honda Prelude Forum

a1andres · 12-01-2001, 10:58 AM

Ok After installing my Greddy header, I went and removed the heat shield off of the Cat because I suspected it was making a rattling sound.. Well THAT rattle went away, however whenever the car gets good and warmed up there seems to be a rattle coming from the CAT... it is most noticable when dropping down from 4k down to 2k if I am coasting to a stop.. then when I rev the engine in neutral I can get some more rattle out of the bastard... I went and got underneath the car and everything is as tight as it is going to get..

So is this a sign that my cat is going bad?? should I just go ahead and replace it? as far as I know it is the original cat and the car has 136K miles on it.. so should I bite the bullet??? WHo makes a direct bolt on Cat for our car?? I figure I might as well go high flow since I am replacing the part... Is Random Technologies the only company?? What are some good prices?? I have seen them for around 200 bux.. is that reasonable???

Machine Head · 12-01-2001, 02:08 PM

does you exhaust stink? if so you need a new cat.. If you need a new one I have a direct fit oem spec brandnew I'll sell to you for $50+ shipping, a screw up gave me two.

$200 -$250 is avg for a random. But don't expecpt much in the HP area. maybe 1-2 if your lucky.

remember you want Some back pressure, it acts as a scavenger to help vacume out the exhaust...unless your going turbo

H23Lude · 12-01-2001, 03:19 PM

yes your cat may be bad. But cats dont go bad for no reason.

You might need a new o2 sensor or something else that caused it. Or maybe a major tune-up. Usually its something that caused the cat to blow out, they dont just go bad. So you might want to get it checked out.

Mike95lude · 12-01-2001, 04:06 PM

I know your exact problem.
Your o2 sensor is loose and rattling. It happened to me after I put on my header.

Just tighten it down again, problem solved.