2015 Tahoe/Bad catalytic converter

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DixieL

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I have a 2015 Tahoe that I recently had the catalytic converter replaced with an aftermarket one. Drove 2 weeks and the engine light came back on, they reset and I drove it for a while, light came back on. Took it back in and they replaced the cat again thinking it was a bad part. Drove another 2 weeks and the light is back on. Mechanic said sometimes tahoes don’t like aftermarket cats and if I want it fixed I’ll need to pay the difference for an OEM one. Does this sound right?
 

OR VietVet

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Welcome to the forum.

I agree that with emission parts, the OE GM stuff is best but I would also want to know what the code(s) are. What was the diagnostic process? I can assure you that there is no code that comes right out and says a cat is bad. Bad readings and reactions, yes. But what caused that. The cats may start out ok but something upstream is damaging them quickly. Need to know those codes.
 

Miami-Dade

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I have a 2015 Tahoe that I recently had the catalytic converter replaced with an aftermarket one. Drove 2 weeks and the engine light came back on, they reset and I drove it for a while, light came back on. Took it back in and they replaced the cat again thinking it was a bad part. Drove another 2 weeks and the light is back on. Mechanic said sometimes tahoes don’t like aftermarket cats and if I want it fixed I’ll need to pay the difference for an OEM one. Does this sound right?
PLEASE use Only OEM products on your 2015 Tahoe from here on in. On Everything.

Welcome from Miami Beach&Queens NY.
 

Sam Harris

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FWIW, my ‘03 has ARH longtubes, with cats, and she’s never complained about them. Not really apples to apples, but as @OR VietVet stated above, the shop needs to specify what troubleshooting they performed, what codes were read, etc.. having them installed for only 2 weeks, and experiencing this issue seems pretty shady. Where were the cats obtained from? They could be improper for the vehicle.
 

swathdiver

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I had each of them for only 2 weeks, that fast?
Could be. Or something is still wrong with the engine and killing them. There is also a caveat that a new cat will often set a code within the first 50-100 miles as it breaks in.

A massive exhaust leak on that side of the engine can throw a cat code to set too.

Would be nice to view the failure records stored in the computer when the code set.
 

Doubeleive

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sounds shady but like others said you need to take a more in depth look at what is going on.
one thing I would do is verify the part is what they said it is, get under there and look at the numbers stamped on the cat and make sure it is the correct one and matches what they said was installed and be sure it is the correct one for your vehicle.
what is the mileage? 02 sensors are rated for 100k and then all 4 should be replaced
take a look at the welds and see if there is black soot coming out anywhere or any leak sounds
fuel trims should probably be looked at as well as 02 sensor live data, see if any of the sensors are lazy
have any other modifications been done?
I have burnt thru cat's before as fast as 6 months. 2-weeks is way too fast I would bet there is something else at fault or it's a junk cat
if it turns out that everything else checks out then you need to get all your ducks on a row and take it up with the vendor and get it replaced.
 

Palooza

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Wondering how you made out with this? I replaced the cat on my 2017 Yukon Xl 5.3L with a Davico 19720 and the light stayed on. The garage also said the aftermarket cats are the problem despite that it has a 25000 mile’s warranty. How can they sell any of these if it won’t clear the code?

I have P0420 on bank 1 and P0430 on bank 2.
 

labmom

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Probably had something to do with your brake vaccum pump. Mine did a lot of strange things before we figured out our pump was failing
 

SpyShops212

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PLEASE use Only OEM products on your 2015 Tahoe from here on in. On Everything.

Welcome from Miami Beach&Queens NY.
Except the upper and lower front control arms. Duralast Gold from Autozone is better. They cost 15-20% more. When you compare the OEM and the Duralast you will see what I am talking about.The Duralast has lifetime warranty and zerk grease fittings. I also would only use the Duralast AGM platinum battery from Autozone. If the battery fails you could drive to any autozone and get it replaced on the spot. Autozone will let you use there tools or change it for you too. I made the mistake by buying a Delco GM gold 40 month battery and it failed 9 months later. I was stuck and had to wait for roadside. I thought maybe my battery needed to be charged so I drove it and again I have to call roadside x2. In order to get my battery warrantied I had to bring my Escalade to the Cadillac dealer that sold me the battery and leave it for a few days. I was out of town so I wasn’t able to do it so I just purchased a Duralast just to be done with it. So I basically threw away $220 by purchasing the Delco Gold. It was a hassle to get it warrantied and didn’t want to keep calling roadside everywhere I went. This happened on a Friday night so the dealer wasn’t open till Monday which meant I had to keep jump starting my truck throughout the weekend putting my truck as risk and possibly breaking the computer or something else. The Duralast AGM battery is awesome. I had it for almost a year. I am very happy and it has great reserve. I like the way it looks in my engine compartment too.
 
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SpyShops212

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Look how beautiful the Duralast Gold upper and lower control arms look with my OEM sway-bar end-link! I also replaced the upper and lower insulator and isolator. This was my 2008 Escalade that had 207k and lived in NYC Queens from 2008-2021 1/2. We had some of the worst weather storms some years was record like Xmas 2010, 2016 & 2018. I kept my truck clean with wd-40 and pressure cleaning it every other year. My springs, hub bearing & knuckle was original as well.

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SpyShops212

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How did this thread go from catalytic covertor to suspension? What did I miss?
Lol…..Because the topic came up about using OEM parts so I was suggesting from experience some OEM parts are not the best. Just wanted to put it out there what is the best if you decide to replace the front end parts. This is something that will need replacement shortly after the catalytic converter.
 

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