Why would a Catalytic Converter be replaced twice in 3 months?

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SeaNeat2053@reddit (OP)

This is such a simple yet correct answer, that I almost feel embarrassed having asked

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geek66@reddit

Possibly way too much oil burn - but you would notice this if you were next to the car when running.

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unbroken_cycle@reddit

Sedan is lower to the ground, right? Reduced theft opportunity

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Not really. Old Hondas and Acuras are prime targets since their cats have more precious medals and bring in more money. Thieves stole my 02 Acura CL's cat and a similar year Accord across the street while passing up on my RDX and a bunch of other SUVs. Older Prius trend to be desirable targets too.

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AC-burg@reddit

If it is a true dual exhaust it has 2. If 1 went out and they were the same age the 2nd coukd have gone put close to the same time

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rklug1521@reddit

And/or they could have replaced it with a cheap part that kept setting off the check engine light and then replaced it with a better part.

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SusheeMonster@reddit

I wonder if the original owner considered adding replacement cat converters to the maintenance budget, then said fuck it and got a sedan 🤔

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Living_Fig_6386@reddit

I had taken one of our old cars to the mechanic for some brake service and left it overnight. During the night someone broke into their lot and stole all the catalytic converters off the all the cars. They called me the next day to tell me their insurance was buying me a new one.

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Scared_Bell3366@reddit

Coworker had one stolen and took it to a local mechanic to get it replaced. It was stolen again at the mechanic’s shop before he could pick it up.

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Desperate_Set_7708@reddit

And easier on a truck given ground clearance and accessibility

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Viking2151@reddit

Probably theft or bought aftermarket ones that didn't really work or they don't know what they are doing. I know in my county they don't do echecks and cat theft is kinda high, normally seems to happen to people that don't have much money to begin with, usually end up just throwing a pipe in place where it was and call it good.

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Eagle_Fang135@reddit

Does it have more than one? My car had dual exhaust so 2 cats.

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Brilliant-Onion2129@reddit

Your engine is running like shit!

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mxracer888@reddit

I'm more curious as to why Carfax has that data at all lol guess they've started aggregating more data

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Unlikely-Act-7950@reddit

It's possible it had a engine performance issue that's damaging to converter.

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Cold_Exchange_8346@reddit

This is why I removed mine myself. No one can steal it if it’s not there to begin with 😜

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One_Evil_Monkey@reddit

Lierally **my first guess would be theft** *if* my scanner didn't show anything code wise or give me any weird live data readings.

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Some_How_I_Manage@reddit

I mean, if it is a V6 or V8, there are 2 catalytic converters typically. Maybe they failed close to each other?

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iamnoone815@reddit

Because it was stolen twice in 3 months

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MansomeHan@reddit

Burning oil.

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EasyPart7258@reddit

If its a V8 it probably has two of them

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Diligent-Body-5062@reddit

Oil leaking past piston rings fouling it, being stolen?

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WuTangwhite426@reddit

Misfire. Misfires will roach a cat especially in small engines. So the fuel and air fill the cylinder like it's supposed to and doesn't ignite. It the pumps out the exhaust valve into the exhaust system. Cats are the hottest part. The fuel and air ignite in the car, blowing it all to hell.

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onedelta89@reddit

Stolen

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WuTangwhite426@reddit

Misfire especially in smaller engines will toast a cat

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1995LexusLS400@reddit

It got stolen, owner replaced it, thief came back and stole it again. It's pretty common.

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Content-Insect-8770@reddit

Could be theft or it could be a 2nd catalytic converter. Many cars have two, and they were trying to fix a stubborn problem. Or they indeed could have destroyed their catalytic converter twice if (for example) there was an engine problem that was causing to much unburnt fuel to leave in the exhaust and then detonate in the CC. Not necessarily a red flag, but I'd be curious to look at how many miles/km since any codes were reset. If it was very recent, that'd be a red flag for me.

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Far-Drawing-4444@reddit

Most likely theft. A catalytic converter should last decades, unless they tried using one off Temu or something the first time.

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Beginning_Ad8663@reddit

Blown head gasket allowing coolant into the exhaust system.

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Heavy_Gap_5047@reddit

Why do people post questions like this with no info, like we're just supposed to pull an answer from our ass?

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DFLDrew@reddit

There’s a condition causing the engine to run rich. The fouled cat is the symptom, not the problem. Just a hunch, though. Could also be a lean condition burning it up?

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