Side effects of clogged cat?

[Toneloc5145]

I was thinking about maintenance that I am going to do this upcoming summer to my car, and I was wondering what the side effects are of a clogged catalytic converter? I would think that after 18 years of use, a new cat would be in dire need, but maybe I'm wrong.

[88Accord-DX]

Probably the worse case scenario is too much back-pressure causing the car to stumble under heavy throttle. I have seen a car not go past 30 mph with clogged cat. A clogged cat will cause the engine to miss-fire too.
You can test for clogged cats with a back-pressure gauge in the 02 sensor, or vacuum gauge hooked up to the intake, & laser thermometer.

[Hauntd ca3]

worst case i've seen is that there is excess heat build up and the carpets can melt or possibly catch fire.
if local laws dont require one, throw it away.
just make sure you earth the cat temp sensor to the body.
otherwise you get the cat light on the dash all the time.

[Toneloc5145]

worst case i've seen is that there is excess heat build up and the carpets can melt or possibly catch fire.
if local laws dont require one, throw it away.
just make sure you earth the cat temp sensor to the body.
otherwise you get the cat light on the dash all the time.

I'm carb'd so I don't think I'll have that problem. But I need to have a cat where I'm at, and I guess my cat is working fine, since I have no where near the problems you guys have said, but I just figured it would need to be changed after so many years of use.

[thegreatdane]

The cat will get extremely hot if it's clogged, and you might even be able to feel that the amount of exhaust gas exiting the exhaust seems reduced. Sometimes a cat just blows out it's own guts instead, so it's completely empty.

[AccordB20A]

worst case i've seen is that there is excess heat build up and the carpets can melt or possibly catch fire.
if local laws dont require one, throw it away.
just make sure you earth the cat temp sensor to the body.
otherwise you get the cat light on the dash all the time.

dont throw it away if its still got its insides they are worth scrap $$$$

[2oodoor]

^^^ umm excessive hairball discharge
umm someone mistaking your kitty for a pekinese dog
umm you left the house with two mylar garfield baloons and now there are three
umm things that go pop in the night
umm the fish in the aquarium are all smiling at each other
umm you accedently grab the cat and plug it in thinking it is the dirt devil vac

[88Accord-DX]

The cat will get extremely hot if it's clogged, and you might even be able to feel that the amount of exhaust gas exiting the exhaust seems reduced.

If you have a laser thermometer, it shouldn't vary more than 100 degrees from the inlet to the outlet side of the catalytic converter. If it don't, then it's not properly working to it's full potential.

[M3Galaxie]

^would that test work with a sensitive touch thermometer?...is it the temperature of the pipe itself or does it have to be a laser thermometer? My car has a little bit of a stumble when accelerating hard just not very smooth. I have to pass smog...hopefully the law changes pretty soon then it gone.

[88Accord-DX]

would that test work with a sensitive touch thermometer?...is it the temperature of the pipe itself or does it have to be a laser thermometer?

Laser thermometer hits where the front of the catalytic converter starts & ends to measure temperature. You can try to use a thermometer with a probe on the end of it, but might not be real accurate. Probably one way for you to see if it is bad, is to run the engine for 20 minutes & see if the cat is glowing red. If it is, it is bad.

[2oodoor]

Laser thermometer hits where the front of the catalytic converter starts & ends to measure temperature. You can try to use a thermometer with a probe on the end of it, but might not be real accurate. Probably one way for you to see if it is bad, is to run the engine for 20 minutes & see if the cat is glowing red. If it is, it is bad.

yaa think?

infrared is the best, you dont have to get near it .. it will read in up to 1200 degrees sometimes with clogged converter.
I love my infrared , mine doesnt have laser mark on it though, still it works wonders .. I found out everywhere my house needed insulation right thru the walls and ceiling. You can tell which brake is giving problems with just a point, bad bearings, pulley bearings, lean cylinders, endless uses once you understand them.

[2oodoor]

I know for a fact you can find a clogged cat with it, that bastard can be inside the couch, behind furniture, and all you have to do it point it around and watch the temp readings, when it goes warmer than the surroundings,, bingo there it is.
It reads right through objects.

[mushroom_toy]

Thats why Im glad I live in a place with no emissions testing. Gutted cat for me.

[bank2me]

I think one side affect of a clogged cat is a rotten egg smell but I'm not sure though. We don't have emmissions test here either.

[86nlife2go]

lol at roodoo and his "clogged cat". I have heard the rotten smell thing to. Most of the time the cat has been either gutted or tossed long before I can afford to buy the car.

[bushbean]

My Geo Storm had a clogged exhaust from broken down pieces of catalytic converter. The cat was made out of a cookie like material, so it can break down inside the cat housing. I was driving down the freeway, and all of a sudden, there was smoke coming out of the dashboard and engine lost power. I pulled over. The engine still ran, but wouldn't go pass 1500 RPM. The car had to be towed home.

[Dr_Snooz]

^^^ umm excessive hairball discharge
umm someone mistaking your kitty for a pekinese dog
umm you left the house with two mylar garfield baloons and now there are three
umm things that go pop in the night
umm the fish in the aquarium are all smiling at each other
umm you accedently grab the cat and plug it in thinking it is the dirt devil vac