Cherry Red Catalytic Converter

[Braddock]

Would the caty be responsible for the lawnmower noise when reving and the smoke in carb?

[IsaacHayes]

Cat is def bad. It may have gone bad from a rich mixture, but yeah it's toast and yes a clogged cat will cause power loss that gets worse and worse.

Take it off, or hollow it out, and then determine how it runs and if it's still too rich. Once you have verified the car is running good again, then replace the cat if you have emissions in your area with a new one. Don't want to install one until you know the car is running a-ok and not too rich or it will ruin a new one.

What superdave said basically (I should of read down before replying!)

[Superdave]

either way, the cat is bad... replace it ASAP before it causes a fire or engine damage.


If you think you have other problems then i'd suggest installing a "test pipe" instead of a cat while troubleshooting your carb. Then of course, install a cat (hi-flow's can be had for about $50 on ebay) and enjoy.

[Braddock]

The name says it all. I know it's either clogged, or rich mixture. But I cant seem to figure out which. Here is how I got to this point.

So I was experiencing loss of power. Was getting worse every day. Got to the point the car would stall when the power steering was used to make a turn. So i made it take me home and that was its last time on the road.

So I start fuckin with it, at first it runs still with the air filter off, then not even like that, had to have my buddy finger the carb to give it enough air to start. Figured my carb/choke had it and was giving it a bad mixture so I thought Id pick up a new carb from the yard and throw it on there.
(PS, timing and spark and all the electrical shit was/still is fine)

So, It does decide to run, but spits grey smoke and *what seems like gas vapors?* from the pipe in the back. We once again check timing, adjust idle speed nice and all the good stuff and it stops spreypainting my driveway with gas. We figure after checking a few seals for an unrelated oil leak, we'd be good to go, but it wasnt to be. I smell an aweful burning smell and started looking around for it and i notice the driveway under the car is illuminated red. Scared shitless thinking my car is on fire, i dive down and find my catalytic converter cherry red and smoke bellowing from under the car! Of course I turned off the car and let it cool under supervision with the garden hose ready(didnt want to use at risk of cracking something from sudden temp change)

Here is a basic run down of symptoms:

-Smoke from carb air intake upon turn off of car
-Catalytic converter didnt do this till after I sealed leaks on mating surfaces of exhaust manifold(before that exhaust came out from leaks)
-Engine sounds smooth idling, but when reved a nasty lawnmower sound comes from carb.
-chugging noise from tailpipe
-spark plugs seem fine, no significant indication of rich mixture. however the plugs are relatively new(April) and have about 5000-6000Km on em. And the power loss problem didnt come about until September.

My reason for asking with such detail is that both a clogged Catalytic Converter and a bad carb(potentially producing an overrich fuel mixture) can cause loss of power causing the initial problem to begin with, but the carb has been replaced now, and i never noticed the overheated Catalytic Converter until today(Not that it may not have overheated before)

Is there anything i should look for which would give me a better idea if the carb or the catalytic converter is the cause of all this grief?