Questions tagged [catalytic-converter]

Device placed within the exhaust system used to catalyze pollutant gasses found in exhaust gasses. Is normally located after the exhaust header, but before the muffler. Can be configured as 2-way or a 3-way: the 2-way affecting hydro-carbons (HC) and Carbon-monoxide (CO) gasses; the 3-way affects Nitrogen Oxide (NOx - do not confuse with Nitrous Oxide or NO2) as well.

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16
votes
3answers
11k views

How can I tell if I have bad cats?

No, not that cat! Catalytic converters - or "cats" - have a nasty habit of failing with age. What are the symptoms associated with a cat that's gone bad? Are there any tests that could definitively ...
8
votes
6answers
141k views

Is it a good idea to remove the catalytic converter?

Some people have suggested that I remove my cars catalytic converter. This is because my car is designed for a different market, and the manufacturer recommended fuel is not sold in my area. It is ...
5
votes
1answer
13k views

How to determine if P0430 is O2 or catalytic converter

2009 CTS4 3.6L P0430 catalyst below efficiency bank 2 comes on periodically. (There are no other codes being thrown.) I put a data logger on it today on my drive to work and the rear sensor is ...
11
votes
3answers
19k views

Is the catalytic converter broken? An odd rope is coming out of the exhaust pipe

Old Volvo GL 440 and this is coming out of the exhaust pipe. No noise, all working fine but this cosmetic thing: does it mean that the exhaust gases are now not well filtered out? Does this mean that ...
11
votes
3answers
103k views

Check Engine code P0420 Catalyst efficiency below threshold bank 1

After months of normal driving with no problems, my 2003 Honda Civic EX check engine light came on during a long trip. Got it scanned and it's P0420: Catalyst efficiency below threshold bank 1. They ...
8
votes
1answer
216 views

Breaking in a new catlytic converter?

I read somewhere you need to break in a new catalytic converter. To that end: Is this accurate? What is the purpose of breaking one in? How do you break it in?
12
votes
1answer
7k views

What are the tell tale signs of a catalytic converter that might be going bad?

I've owned two vehicles whose catalytic converters were recalled due two a couple of reasons: one being the quality of the CC and the other being a reduction in power due to a material building up and ...
7
votes
3answers
22k views

Can A Catalytic Converter Fail Due to Age?

Suppose that a car has 120,000 miles on it and the catalytic converter fails. From what I read (see here as an example), age doesn't appear to be a general cause for failure. Is this a possibility ...
10
votes
1answer
6k views

Can a head gasket leak cause the cat to plug?

Well, like the title reads ... I replaced the heads on a Dodge Ram V8 5.9L gas engine. It's now running like the cat is plugged. Can blowing the white plume of coolant exhaust out the tailpipe cause ...
7
votes
3answers
2k views

2003 Toyota Corolla, 185k: erratic OBD codes, fuel smell, other symptoms

TL;DR: O2 sensor data, thermal measurements, and physical resonance tests all point to a failed Catalytic converter. Here's the back story. MIL illuminated with codes P0440, P0420, P0404. Around this ...
7
votes
1answer
753 views

Locating the O2 sensors and the cat along the exhaust

I gather that the upstream O2 sensor is the one right in the center of this picture. I also gather that the catalytic converter (the "cat") is the bulbous part of the exhaust right behind this sensor. ...
3
votes
2answers
3k views

Catalytic converter readiness monitor never sets

I Reset the computer in my 1998 Chevy Astro, but even after driving around for a few days and putting it through the GM drive cycle, the OBDII reader is saying that the CAT monitor is not ready. I ...
2
votes
1answer
340 views

Car stalls on intersection or when coming to a stop

I have a 2000 Mazda 323F (some say it is Protégé but not sure) AT 1.6L (at 128K km). It runs smooth, accelerates great and shifts nice on most occasions. But there are times after running for a ...