Do I really need a new Catalytic Converter?
Posted by OptimalPollution1852@reddit | askcarguys | View on Reddit | 11 comments
I have a 2022 Kia Soul with about 96,000 miles on it. About a month and a half ago while I was parked it idled a little rough and died, then she cranked right back up no problem, but the check engine light came on. But then it went away after a couple days and she didn't act funny what-so-ever. Then the same thing happened again about a week ago, and the check engine light came back on. Well I went yesterday to advance, first I bought a engine air filter because Google said to try that first. The one in the car wasn't even that dirty but I swapped it anyway. Then I asked the associate to run the computer on it and it came back with the code P0420(1/2) stored. Catalytic Efficiency below Threshold (Bank 1) DTC severity 2 of 3.
This is all Latin to me, but I know a Catalytic Converter issue is bad. The associate told me to take it to Kia ASAP, so I did, and the guy didn't even look at my car. He just told me that if they switched it I'd be looking at a lot of money, and I'd be better off going to a different, trusted mechanic or trading it in all together.
I called my brother who knows a little bit about cars and he ran some seafoam through the vacuum and reset the sensor so the engine light is gone for now. He had said it'd would smoke out a little after the treatment, but it didn't smoke at all. I've driven it about 40 miles since then (back to my house, and then to work this morning) and she seems fine. I'm a little freaked out though because either way, I cannot afford a whole new converter. I don't want to believe it's that serious when she's not doing anything crazy. So I wanted to check in here and see if anyone had any ideas as to what to do or what the issue may be. Thank you in advance!
ratedsar@reddit
For a 2022, not unless you've been driving with a failed (read super rich) fuel and ignition system (CEL would stay on)
It seems most likely an O2 sensor needs to be replaced; though that this happened when starting also adds in a secondary air pump possibility. The rough idling also makes it seem like a misfire (spark plugs or coilpack issue)
Glittering-Ad5809@reddit
Some states like CA require cats to have a 120,000 mile warranty.
limited_instincts@reddit
It's WAY more common for that code to pop up because of the O2 sensor than the cat. Especially at 100k miles. In 30+ years of owning cars I've never once had to replace a cat and I've probably done 20 O2 sensors.
FYI whatever chump told you to "take it to Kia ASAP" is not someone to ever go back to. Just find you a trusted local mechanic and use them.
jrileyy229@reddit
It depends on the state... But basically what he's telling you is that at the dealership they are only going to use OEM cats and full blown retail with full blown retail labor. Could easily be 3k. I don't know KIA at all, just spit balling an example.
You go to small shop who uses an aftermarket cat that might be 1/10th the price with reasonable labor and you might be out the door for a grand.
Upstairs_Art11@reddit
Honestly I wouldn’t panic and assume the cat is completely dead yet. I’ve seen P0420 come and go from misfires, fuel issues, or sensors too, especially if the car still drives mostly normal. The rough idle/stalling part feels like an important clue and not just “bad catalytic converter = replace immediately.”
WittyFix6553@reddit
I’ve had a 0420 on my RSX for months that just comes and goes.
I’ll worry about it when I need to get it inspected.
Upstairs_Art11@reddit
Yeah honestly that’s kinda how a lot of P0420 situations seem to go at first. The “comes and goes” part is why I wouldn’t immediately assume the cat itself is completely toast yet, especially if the car still runs mostly fine.
Sweet_Baby_Cheezus@reddit
So, the check engine light let's you know when your car's emissions are out of wack. That can mean running too rich, or too lean (too much/little gas per oxygen).
Your catalytic converter is environmental protection, it turns Nitrous Oxide into Nitrogen and Oxygen and Carbon dioxide into Carbon Monoxide.
Sometimes the oxygen sensors get clogged over time and can misreport. The platinum in your catalytic converter also breaks down over time leading to "dirtier" exhaust which can be reported as a check engine.
A catalytic converter isn't really necessary for the operation of the car (unless you're in a state that tests emissions), it also isn't too expensive or hard to replace, I'd guess around $500 for an aftermarket one done at a independent mechanic. They just cut the old one out and weld a new one in.
Honestly, if the lights gone, you probably don't have to worry about it. It sounds like a sensor misread. If it comes back, take it to an independent mechanic, see what they say cost wise, then evalutate if you're willing to take the risk of just driving with the light on.
GoBlueBeatOSU21@reddit
I've been driving my car with a cat code for the last 4 years. I wasn't worried about it but my wife was. I called my mechanic on speaker with my wife listening and they confirmed it wasn't a big deal if the car was driving normally. They said they could put on an aftermarket cat which would be less expensive than an OEM if I really wanted it, but there was no guarantee the check engine light would go off with an aftermarket cat.
The real issue is if it's clogged enough to cause issues with how the engine runs.
You also should fix whatever caused the problem in the first place, what caused mine was a bad ignition coil.
ollieottah@reddit
420 isn't normally a cat unless you have an unresolved issue that you ignored for a long to. With the milage, you probably need a tune up. Take it to an automotive technician for proper diagnostic. A clogged cat will normally have very noticable drivability issues. You'll normally have very limited acceleration and the car will sound wrong when accelerating.
NotMuch2@reddit
Codes are not a diagnosis, just a clue. Could be a sensor related issue that measures the output of the cat. Get a proper diagnosis from a qualified mechanic.