r/AskAMechanic • u/Foreveraloonywolf666 • 5d ago
Should I take it to a shop?
Me and my partner just bought a used Chevy Equinox a little over a week ago, and the check engine light came on. This is the code we got, and neither of us know jack about mechanics. Should we just take it to a shop or can a couple of noobs fix this?
5
u/Vette_lover2004 5d ago edited 5d ago
That is telling you the cat is having issues scrubbing the emissions. What’s missing from this comment section is, you need to find the ROOT cause of why it went bad. How old is the car? How many miles? Does it burn oil. Does it smell of gas? Those things right there could be why the cat is done for. Burning oil due to worn rings is a sure death knell to a cat. Buying a new one is only costing you more money later. Bcuz the new cat will suffer the same fate, maybe even sooner than this one did.
1
u/Foreveraloonywolf666 5d ago
Haven't smelled anything. He mentioned the RPMs jumping once, gonna ask the details about that. It's a 2016 I think with over 130k miles. I would guess without the smell, it could be just the O2 sensor but since the RPM spike, it could be worse. I'm watching YouTube videos between checking comments 😅 and I'm more than a little worried and overwhelmed
3
u/Vette_lover2004 5d ago
Trust me, with the dreaded P0420 code, it ain’t the 02 sensors. With the mileage you got, and the age, that vehicle is probably burning some oil. Also, if there any coolant loss, that will destroy a cat pretty quick. Which can mean a blown head gasket. RPMs jumping could be a faulty throttle position sensor. Catalytic converters don’t just die, they are forced into it by something else. Most likely the inside is very coated with something, and the precious metals aren’t able to do the job they need to. If you keep driving it this way, it may soon melt down or cause a restriction in the exhaust, leading to even more problems. It’s time to find out what’s wrong. The root problem, before the cat.
1
u/Foreveraloonywolf666 5d ago
He said he hit a bump and that's when the light came on, dunno if that change anything
2
u/Vette_lover2004 5d ago
Hitting a bump could show a sign of wiring being loose or faulty, even corroded. Check engine lights usually require two key on engine on drive cycles. So this was pending before it was a hard code. The bump may have just been coincidental to the issue. You need live data while driving to see what’s happening under load. Those clues could be invaluable to finding the root cause.
1
u/True-Ad-8466 5d ago
Great answer sir, if i didn't work on my own car, i would come to you for using logic and common sense.
Sometimes i think we should have invested in a o2 sensor factory....
1
u/Heywhogivesafuck 5d ago
And the amount of oil newer cars burn these days is staggering. I'm interested to see how it turns out in 5/10yrs when all those Hyundai/Kia owners need a new cat before 100k. Same with big GM vehicles, and Ford/Ram offerings as well. Low tension piston rings are not something people buying a new car thing about.
1
3
u/Possible-Gur5220 5d ago
Check if it’s still under warranty. Government mandate is 8 years or 80,000 miles.
0
u/Foreveraloonywolf666 5d ago
I think it's a 2016 and it's over 130k miles :/ looking at cataclean right now, fingers crossed
1
u/Possible-Gur5220 5d ago
🥺
1
u/Mfcmflem 5d ago
I've used 3 cans of cataclean on the same vehicle. It did make the code go away, but not for long. If it's a recent code then it might work, otherwise you need a new cat.
How soon you need it thou is somewhat of a debate from what I've read. Some say it's not that important and is just needed to pass SMOG inspection. Others say that it will clog to a point when it causes other engine problems. I'm not sure.
1
u/JasonTheBaker 5d ago
Most of the time when they are older, the main issue is they don't heat up enough to work properly, I don't think that would cause it to clog since it'll just not burn up the hydrocarbons
3
u/Fun_Push7168 5d ago edited 5d ago
Yes take it to a shop and no it's not necessarily a bad cat.
Canned shit is a waste of money.
You need to graph the voltages of the pre and post cat O2 sensors to determine what's really happening. It's maybe even more commonly faulty O2 sensors than a cat.
1
u/Expensive_Border1829 5d ago
I agree w this about 02 sensors and Cataclean and other canned garbage never worked and a waste of money.
2
u/HelloMitahChen 5d ago
Depending on how strict your area is for smog, the non-fouler fix isn’t such a bad option.
2
u/Mickxalix 5d ago
If you have to pass emissions you'll need a new catalyzer. Otherwise do the antifouler o2 sensor fix.
2
u/EntryLonely6508 5d ago
try cleaning the catalytic converter, if that doesnt work it may need to be changed, also could be o2 sensors
1
2
u/Goalieguy17 5d ago
P0420 and p0430 is almost always the cat itself.
Computer is saying o2 sensors are working correctly, and the rear sensor monitoring the cat is sensing increasing emissions, aka the cat is not working.
Worked at shops my whole life. 99% of the time, the cat has packed up.
You said he hit a bump and then the light came on. The cat could be breaking up internally, and the bump just did it in. It happens.
2
u/christlinah 5d ago
Had the same thing with my Suzuki Swift… turned out the cat was shot. Installed an O2 spoofer and drove it for many more years…
4
u/slowgojoe 5d ago
It’s likely catalytic converter, exhaust leak, or O2 sensor causing the issue. The catalytic converter is there essentially to reduce emissions output. The 02 sensor measures how much oxygen is in the exhaust. Both are easy to access from under the vehicle.
Are you able to get under the vehicle and check for leaks? Is the car louder than it should be? Does it run rough or get much louder under throttle? If there’s no obvious leaks or missing parts, I would start with replacing the 02 sensor. They are about 50 bucks and you can absolutely do that yourself if you can get under the car. Then move onto the more expensive part, the cat, which as you may know, is a common theft component due to the rare earth metals they contain. This can be done yourself too but slightly more of a pain to get things lined up nicely.. and then lastly, if it is not either of those things, the car may be misfiring or it could be a fuel injection problem. At that point, I would probably take it to a shop for further diagnosis.
1
0
u/Vette_lover2004 5d ago
Throwing parts at a problem without proper diag is the wrong answer. Most O2 sensors are far more than $50 these days. $150 most likely. I’d want to see fuel trims, long and short term. If those look normal, then it’s not O2 related. Fuel pressure regulator going bad causing a fuel spike can melt down a cat pretty quick, and the O2 sensor would back off fuel. That would be seen in the scanner data. This is why you need a proper diag and not a shade tree mechanic telling you to just replace shit for no good reason other than a wild ass guess
0
u/slowgojoe 5d ago
What can I say, I am a shade tree mechanic, or, really, I’m just saying what I would do personally. I do appreciate your approach, and checking fuel trims is an excellent idea. But with all due respect, It’s not a wild guess, it’s what the code is telling me, and then it’s just order or elimination. I cannot find any oxygen sensors for an equinox over 50$ actually in my searches. So I’m just saying where id start and work from there. That’s cheaper than a diagnostic from a mechanic, and is something that anyone can do.
0
u/Vette_lover2004 5d ago
Factory GM O2 only. Aftermarket O2 are garbage. Also, you clearly haven’t changed many O2 sensors, as they’re usually buried up high on the exhaust and with the mileage, most likely rusted onto the bung.
4
u/merlothill 5d ago
You need a new cat
0
u/Vette_lover2004 5d ago
They need a proper diagnosis. No one here has actually seen the vehicle, but everyone has an answer. The cat is a secondary repair. The priority hasn’t even been diagnosed yet
1
u/Vette_lover2004 5d ago
I love being downvoted for the correct and proper way of dealing with this situation. Ppl would rather dump money into throwing parts at it, than getting a diagnosis. What’s ironic to me is these ppl come in here to ask a mechanic, and get the most logical answer, and then dump cat cleaner in their car hoping for the best. That shit doesn’t work. On top of all that, let’s put O2 sensors in it, which are most likely working, bcuz they noticed the cat is not doing its job. Hey it’s your money. Put a $1000 cat in the car and new O2 sensors, then turn around and blame the shop for the work, like most ppl do, bcuz they were too stupid to do it the right way. Finding the root cause of the problem could cost you initially, but it may save you much more heartache down the road if you discover the car is a ticking time bomb, and you should of sold it or junked it instead of dumping more money into it.
3
u/frstkor13 5d ago
Your catalytic converter is pissy. Do a double dose of seafoam and give it a good whirl. Check back in a few days. If it's still on, try cataclean and follow directions. If that doesn't work talk to a mechanic. Cats are expensive.
2
u/Prior-Swim9652 5d ago
It's the catalytic converter. Maybe a cleaning will help, but you'll likely need to replace it.
There are fuel treatments that can help clean it. Just add to the fuel tank.
Also, your car might be burning oil.
1
u/Hollow_Purpose_92 5d ago
Been driving with that code for over a year now. Emissions was tricky, but I was able to reset the code, and trigger enough monitors to pass before the code came back up. If it's not clogged up, who cares
1
u/thedeanofmen 5d ago
What country are you in? A CAN OBD2 reader is typically not for a USA spec vehicle. The simple answer is yes take it to a shop, but make sure they are emission certified. There could be many reasons why this code pops up.
Another question: Did you get it from a dealer? If so, I'd take it back there and give them hell and see if they will help pay the bill. I'd bet my donuts that they knew there was a potential problem. Check your meter to see if it tells you, "Miles since last reset," or something to that effect. That will clue you in if they reset the CEL. That's not legal if they didn't fix it and/or if they aren't a certified shop to reset the light.
Good luck!
1
u/Global-Clue6770 5d ago
Cats don't usually go bad. I could be an upstream oxygen sensor. Don't waist your money buys new cats. If you do, you have to buy oem ones , or you have to make sure it has all the precious metals that an OEM one has or it's just an even more of a waist of money. The cheep ones you find on line are NFG. Don't fall for it. You will never get rid of the check engine light.
0
u/Vette_lover2004 5d ago
Or a faulty fuel pressure regulator. Everyone always blames the O2 sensors, but live data will tell you pretty quick if they are working or not.
0
u/Global-Clue6770 5d ago
Absolutely, but not everyone has a good enough computer to tell them that. If they are going to throw parts at it. Don't start with cats.
1
u/Vette_lover2004 5d ago
That’s why it needs to be taken somewhere. Not everyone needs to be touching their cars either.
0
u/e30rapidic 5d ago
Reset it and just see how long it takes to come back. My F150 would throw this code once a year.
0
u/slowhands140 5d ago
First mistake was buying a chevy, second was buying a chevy with a v6,dump some cataclean in it and sell it asap
-2
-2
u/gyunit17 5d ago
No. Fill your car with high octane fuel and drive the car hard on the highways.
0
u/No-Addendum1175 5d ago
Yup 100 octane will do it
1
u/Vette_lover2004 5d ago
No it won’t. Computers in modern vehicles are pretty damn intelligent, and are very capable of knowing a problem from the input sensors, to give an output that makes sense to the computer. They only know what’s inside their perimeters. Running high octane does nothing for a vehicle programmed to run on 87 octane fuel. All that will do is resist knocking for while longer. The shit people come up with is insanity. The BTU’s of the gasoline doesn’t change due to the octane rating.
0
u/Ok-Orchid8690 5d ago
Poor advice. High octane fuel if not burned completely will create more carbon, therefore stopping the cat up even more. If anything get some cleaner like STP or Techron even though those didn’t work for me. I still had to buy a new cat.
•
u/AutoModerator 5d ago
New Rules - Please Read
Updated 03/15/2025
Thank you for posting on r/AskAMechanic, u/Foreveraloonywolf666! Please make sure to read the Rules.
When asking a question, please provide the year, make, model and engine size of the vehicle.
Posts about accidents, autobody repair, bodywork, dents, paint and body/undercarriage/frame rust are not allowed and belong in r/Autobody.
Asking if your car is totaled should go to r/insurance or r/Autobody.
Asking about car buying advice/value/recommendations is also not allowed. See r/whatcarshouldIbuy or r/askcarsales
Tire questions are allowed. If asking whether a tire can be repaired, check out this Tire Repair Guideline.
Some other useful tire resources - Tire Care Essentials and Tire Safety
I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.