sdhes

How can you tell if you have a clogged catalytic converter? The one under the car is the one I'm concerned with. Just wanting to know what some tell-tail signs are that it might be clogged. Any help appreciated!

tripperfx3

iTrader: (6)

If its really clogged or any part of the exhaust is really clogged for that matter, the car wont start at all. If thats what your running in to just poke some holes in the exhaust just before the cat. and see if that fixes your problem.

Sap12687

iTrader: (11)

Opposed to the one...above the car? Your cat is not clogged.

kfos01

iTrader: (3)

No, opposed to the one in the stock header.

edit: because i can't spell

rice_rocket88

iTrader: (9)

Best way is to check your exhaust flow or idle. A clogged cat essentially clogs it and reduces the flow. If you had a turbo car you would notice it by the decrease in ability to boost. The other thing you may notice is the cat getting hot, ie the gases are getting trapped inside it.

If you can hear a rattling it is also possible that the interior is degrading or separated.

Basically the only true way would be to dis-assemble it and see.

I'm sure the other guys that posted here have never experienced a clogged cat before.... so this is my best advice for you. And of course.. yes, there is only one cat in your exhaust stream

sdhes

What do you mean by check your exhaust flow or idle? How do you do this? Also, just for the Evo guys, Lancer OZ, LS, ES have two catalytic converters, one is inside the exhaust manifold, which I don't have (header), and then the one under the car. I have done some reading on the topic, outside of evom, and it can be clogged without your car dieing. I appreciate the responses so far, thanks

Anyone else?

sdhes

LOL....See, now you have to be carefull with those one liners with the tinge of smarta$$

atilla

iTrader: (9)

if it's really clogged or otherwise pretty screwed up it will heat up big time. at work we've seen cars come in with cats that were almost red hot.

rice_rocket88

iTrader: (9)

Generally my car has an even steady flow of exhaust fumes. When my cat broke apart it would not only rattle a bit (inside)... but the exhaust fumes barely rolled out of the tip (rather than shooting out at a good pace). Also the idle would studder a lot. Seeing as you don't have an Evo, I'd assume your idle is pretty even. (The evo's even stock studder a lot). I would hope that this might help pinpoint such a problem.

sdhes

Thanks, I have been having idle issues for a while that I haven't been able to find the cause of, which has lead me to this possibility. Basicly, my idle is consistant, but there is a rumbling or vibration that feels like it is coming from the exhaust. I guess I could describe it as the idle feels like I have an 8 cylinder. I have exhaust flow out of the tail pipe, but it almost feels like it has too much velocity, like it might possibly be getting metered or pinched by the (possible) clogged cat, much like when you pinch a garden hose, the same amount of water comes out but at a greater pressure. Also when my RPMs are coming down, like when I let off of the gas when approaching a stop sign, The RPMs come down to about 1000 then jump up to like 1700 then as break is applied they come back down to normal idle RPM (600-650). I am wondering if this might not be associated with the increased back pressure from, again, possible clogged cat. As far as the heat, or having a nearly red-hot cat I will look into this. Gas mileage seems to be low which I know may also indicate this problem. I think it might have been caused by running a rising rate FPR from RPW with no fuel managment and a RRM Piggy V1 and basicly running way too rich for a good period of time.

Thanks alot for the responses, they have been helpfull

rice_rocket88

iTrader: (9)

Running too rich for too long may have caused you to meltdown your cat... I think the easiest thing to do would be to take the cat out of the equation.. good luck!

jakermeister

iTrader: (11)

maybe u got a banna in the tail pipe. LOL