signs of a bad catalytic converter ? [Archive] - Honda Prelude Forum : Honda Prelude Forums

: signs of a bad catalytic converter ?


ludeman1
09-11-2007, 10:56 PM
could someone help me with what to look for when your catalytic converter goes bad . I think mine is bad . and some of the symptoms I have are . smells like a lawnmower . hesitation upon acceleration . car seems not as powerful as before . idles kind of funny . sometimes if I,m going into a convience store for a min and come back out to go to start my car , it wont start for about 5 mins. or so [especialy on hot days] / or until I pop the hood and let some of the heat escape from the engine bay for a few.

WashingtonBB2
09-12-2007, 01:44 AM
Im just going out on a limb but I dont think a cat going bad would cause such serious damage like you have described but im not that knowladgeable with cats.

TicketRedBB6
09-12-2007, 06:09 AM
Those do seem like symptoms to me. I had the same problems on a civic and when i took the cat off it was filled with oil and stuff, completely clogged. Just take it off and check it out.

weapon of mass induction
09-12-2007, 09:13 AM
that sounds def like a bad cat... but there is a reason its plugged... how has ur oil level been holding up? and gas mileage? there is something more to it for sure.

ludeman1
09-12-2007, 03:00 PM
oil level is fine , but gas mileage has been suffering !

tsiah
09-12-2007, 03:14 PM
cats dont go bad, they are ruined by some other failure.
smells like a lawn mower? probably running rich (bad O2, bad ECT, leaking injector(s), leaking/bad pressure regulator)

a bad cat smells like bad eggs (but then so does a bad battery :razz: and even to some extent a normal battery when you charge it)

misfires, running rich or running lean, burning oil/coolant, lack of engine maint. will all cause catalytic converter failure.
you need to figure out whats wrong with the engine, then diag the cat.

if you had a 5 gas analyzer you could remove the o2, measure the exhaust gases there, then at the tail pipe and figure out if the cat had failed :razz:

Bobnova
09-12-2007, 04:09 PM
Listen to tsiah, he has teh smartz.


(Seriously though, listen to him)

5spd5thgen
09-12-2007, 04:26 PM
sounds like it might just be a bad o2 sensor

tsiah
09-16-2007, 12:37 PM
Listen to tsiah, he has teh smartz.


(Seriously though, listen to him)
:oh::smilejap: thank you, bobnovasan

ludeman1
09-18-2007, 06:29 PM
I also forgot to mention that its an 87 . and it looks like its never been changed . dont know if that makes any difference

tsiah
09-18-2007, 06:55 PM
cats dont go bad, they are ruined by some other failure.

you need to figure out whats wrong with the engine


:upside:


you could try a test pipe, see if that makes a difference.
catalytic converter failures are not unheard of...so I'm not saying that it isnt bad, I'm just saying you (or previous owner) ruined the cat by not maintaining the engine/other emissions control devices.

ludeman1
09-19-2007, 03:51 PM
thats true , I did just get this about 6 months ago . and have been doing all sorts of maintanence on it , because it looks like previous owner never did anything to this car . I ve put in new injector seals , valve cover gasket , all new belts and hoses . all major tune up components . some performance parts , short RAM intake kit . I am going to put in an oxygen sensor friday . the PGM-FI light keeps coming on giving me a code 12 . I went to pick and pull and got a used EGR valve , but the light just keeps coming on . do you think I would be better off putting a new one on . $ 220 though , ouch !!

ludeman1
09-19-2007, 04:53 PM
I have also just the other day noticed that it smells like a gas leak directly at the fuel pressure regulator . could that be a leaking seal or maybe a bad regulator ?

tsiah
09-19-2007, 06:24 PM
how would your nose be able to tell where a fuel leak is coming from? fuel smells like fuel :dontgetit:

if the regulator is leaking, then it would cause problems (IE running lean)

a fuel leak might explain why you think the car smells like a lawnmower (IE running rich or you're smelling a fuel leak..although partially burned fuel from an engine thats running rich smells a hellava lot different than a fuel leak...)

neonxiii
09-19-2007, 07:02 PM
how would your nose be able to tell where a fuel leak is coming from? fuel smells like fuel :dontgetit:

if the regulator is leaking, then it would cause problems (IE running lean)

a fuel leak might explain why you think the car smells like a lawnmower (IE running rich or you're smelling a fuel leak..although partially burned fuel from an engine thats running rich smells a hellava lot different than a fuel leak...)

the same way when you smell a fart, you look at that one friend

ludeman1
09-19-2007, 07:20 PM
I actually discovered it by just going over the engine where I thought it might be .getting down real close and smelling all the related parts that have to do with gasoline . thats how I discovered the injectors leaking . really then when they were leaking you didnt have to be a rocket scientist to figure it out . very strong gasoline smell , and wet where the gas was leaking out . the injector seals were so far gone , there were about the consistancy of a dry rotted rubber band stting around for about 15 years or so .

mayhem88
09-25-2007, 09:05 AM
sounds like you were running too lean. causes shit tons of heat and when a cylinder is overly lean it wont even fire, itll just dump the fuel air mix into the exhaust and make it smell like shitty scorched spray paint fumes. rich will smell similar tho =) get those seals taken care of and if it still smells like open ass change your o2 sensor

tsiah
09-25-2007, 07:29 PM
you said the pressure reg was leaking...
just by smell? there's no way to verify anything other than "hey I have a fuel leak"
...
:dontgetit:

if there's liquid gasoline spewing from somewhere, then yea, boom, there's your leak.

and leaking injectors is different than leaking injector seals ;)

ludeman1
09-26-2007, 04:20 PM
so your saying I might have bad injector? by the way how would I know if my regulator was going bad . what kind of symptoms should I look for . bad mpg maybe?:eh:

ludeman1
09-26-2007, 04:35 PM
got around to changing the 02 sensor this weekend . let me tell you as easy as it looked , it was the biggest pain in the mutherfuckin ass job I,ve ever had to do to this car .no room to really work . I changed the water pump and was,nt even as much of a pain in the ass compared to the O2 sensor. obviously it had never been changed after 245k it was almost welded in there from all those years of hot cold hot cold . cracked a 7/8 O2 sensor socket trying to get it off with a breaker bar ,it had been in there so long . anyways it did seem to give me all little more power !

mayhem88
09-27-2007, 12:09 AM
lol yeah i had the same problem changing an o2 out. problem is, some dumbfuck put it on without using an antilocking compound on the threads. took a bigass 7/8 6 point box wrench and a 4 foot piece of pipe to break it free