Catalytic converter Melted?

[DunKrS]

Looking at the backside of the cat, what would cause this? The Muffler sounded like it had 15 packets of Ramen broken in it.

Idk if there's enough honeycomb left to even count as being a catalytic converter. =S
My car never has smelt the way most hondas smell. I'm guessing this could be why.
Also how often should an 02 sensor be changed? I was considering changing mine, but don't feel like replacing something if it won't have a positive effect.

[ExplodingCake]

Cat is clogged from the looks of it.

[deevergote]

That's definitely shot. Chuck it (well, sell it to a recycler), and get a good new one.

That is most likely caused by running too rich. Not all the exhaust gas is burned in the combustion chamber, and once the converter gets hot enough, it burns there. Those things get HOT. Has your car been backfiring lately? Is there black soot on your bumper, above the muffler?

The o2 sensor would be a good thing to look at for improper fueling. Normally, if it's bad, your CEL (check engine light) will be on. Make sure the bulb works, and look for the light. If it's on, you need to pull the error codes that it's giving you. Read the "sticky" thread at the top of this section for instructions on how to do that.
Chances are, it'll be code 41 or 43 if it's an o2 sensor issue. Replace the o2 sensor with a Denso or NTK/NGK sensor. DO NOT get a Bosch sensor. They don't work properly.

[DunKrS]

That's definitely shot. Chuck it (well, sell it to a recycler), and get a good new one.

That is most likely caused by running too rich. Not all the exhaust gas is burned in the combustion chamber, and once the converter gets hot enough, it burns there. Those things get HOT. Has your car been backfiring lately? Is there black soot on your bumper, above the muffler?

The o2 sensor would be a good thing to look at for improper fueling. Normally, if it's bad, your CEL (check engine light) will be on. Make sure the bulb works, and look for the light. If it's on, you need to pull the error codes that it's giving you. Read the "sticky" thread at the top of this section for instructions on how to do that.
Chances are, it'll be code 41 or 43 if it's an o2 sensor issue. Replace the o2 sensor with a Denso or NTK/NGK sensor. DO NOT get a Bosch sensor. They don't work properly.

No backfiring, but when I got the car the timing belt was off by 2 teeth, I can't say how long it was like that, but I can imagine this would affect how well the fuel was being burned. It's not throwing a code, I know the CEL works without a doubt, I've just heard that o2 sensors are something that have a lifespan and even without throwing a code, they can give readings that are not optimal for proper A/F ratio.

Car ran near perfect after almost completely overhauling the ignition system after my coil and igniter burned out, and once I got the timing belt timed properly. I didn't notice the catalytic converter issue until my exhaust leaks got so annoying I had to put new 2 1/4" on.

[HonduhKrayzeee]

like deev just said, its caused from running to rich. ur o2 sensor might not be reading right & telling the ecu that it needs more fuel even though it doesnt. the timing being off 2 teeth could very well be the problem. right now my b16 hatch is off by a tooth (maybe 2) and its causing it to run rich which has now caused my o2 sensorS (obd0) to go bad. if your o2 sensor is good reset ur timing & see if that fixes it.

[DunKrS]

Cat is clogged from the looks of it.

Melted but not clogged! There's only 1 of the 3 wafers that should be in there left, it looks like it would clog it though, but i busted the big pieces off, and left what I could because I'm not a fan of the smell without a cat *wheeze* =S

[HonduhKrayzeee]

also the muffler probably sounded like the "ramen" because small/tiny pieces of the comb from the cat have broken off & got blown back into the muffler & are now stuck inside of it.

[deevergote]

The timing belt being off could certainly be a contributing factor, and yes, the o2 sensor may not be giving a correct reading, even without throwing a code.

Replace the o2 sensor with a new one. Even if it's not 100% of the problem, it's still a wear item that's always good to replace!


Also, set your base idle and ignition timing to be within spec. HondaFan81 made very detailed threads for both... I'm not sure if they're included in any stickies now (they should be, but may not have been added to the new ones yet) but you can search for them. Use the Advanced Search. You'll find them quickly.

[DunKrS]

like deev just said, its caused from running to rich. ur o2 sensor might not be reading right & telling the ecu that it needs more fuel even though it doesnt. the timing being off 2 teeth could very well be the problem. right now my b16 hatch is off by a tooth (maybe 2) and its causing it to run rich which has now caused my o2 sensorS (obd0) to go bad. if your o2 sensor is good reset ur timing & see if that fixes it.

Timing has been fixed as of 2 months ago, and it doesn't smell rich necessarily, but doesn't smell like a fine tuned honda should.

Tuning carburetors is great for learning how to smell what a clean mixture smells like, but I never thought about smelling the exhaust with the timing off like it was, I was more concerned with trying to figure out why the car I just bought had NO power.

I know exactly the threads you speak of Deev! And I will replace the o2 sensor right away then, I just wanted to confirm the "wear item" status of it. And the new 2 1/4" pipe made a big difference, it pulls strong to red line instead of nosing off around 4500. I'm assuming a new o2 sensor will definitely help maximize this effect!

[DunKrS]

also the muffler probably sounded like the "ramen" because small/tiny pieces of the comb from the cat have broken off & got blown back into the muffler & are now stuck inside of it.

That, and all the rusty chunks of pipe that blew in there, along with my temporary solution to the leaks (muffler putty, worked pretty well, but it's hard to patch a hole the size of a quarter with goo...) I imagine some pieces of that also made it's way to the muffler, I'm glad that gargantuan hunk of rusty metal is offa my car!

[DunKrS]

Found me a new cat. It was in a car in which the downpipe was uncovered and exposed to the rain. I can still see daylight through the cat and it's completely intact. Do you guys think there'll be any issues having been in water like that? it was wet, but not submerged.

[deevergote]

Give it a shot. Can't be any worse than what you had!

[wed3k]

shake it and see if there are loose pieces otherwise it should be alright. you dont know till you have it tested at a smog emissions station.

[DunKrS]

shake it and see if there are loose pieces otherwise it should be alright. you dont know till you have it tested at a smog emissions station.

And thank god I don't have emissions to worry about around here

[wed3k]

id just get a test pipe and you wouldnt have to worry about anything. a properly functioning cb7 will put out low emissions. i was running my car without a cat and it was pretty good and im in CA where ill get fucked up the asshole if a cop knew. what pissed me off even further is my buddies 99 camaro with no cat's, no egr and no AIR injection was putting out lower emissions than my honda.