Hi everyone,
I have a 2014 Santa Fe Sport with the 2.4L engine. It has 84k miles, but the engine (short block assembly) was replaced under warranty at 65k miles due to excessive oil consumption.
Although the engine was replaced by Hyundai, the spark plugs, catalytic converters, and O2 sensors were not, and were all fouled thanks to the excessive engine oil that was burned.
After my engine was replaced, I replaced the sparkplugs and cleaned the O2 sensors. After all of that, my car ran much better, but it did have a decrease in power that seemed to get worse over time, the mpg was also not where it should have been.
After months of a recurring P0420 code, and gas mileage of only 12-18mpg, I decided to suck it up and replace both O2 sensors with replacement ones from Denso.
This only solved my check engine light for a day or two, before it started to return during every drive cycle after being cleared.
Last week, I sucked it up and finally had a shop replace both catalytic converters. The manifold/cat was replaced with an EPA-approved eBay cat, while the secondary cat was replaced with an OEM cat. I broke the cats in by letting the engine warm up, then driving for 30 minutes at highway speeds, and then shutting off the engine to let it cool down.
I thought this would have stopped my recurring P0420, but it still comes back after every drive cycle. I even disconnected the battery for 30 minutes to reset the computer to no avail.
At this point in time, the code is just an annoyance. My car has more power than it has had in years, and I'm getting 30+ mpg on the highway. Regardless, I want to keep this code away for good.
So, what can I do, and what could be causing the code? Is it because of the cheap eBay cat? Or am I missing something? There are no exhaust leaks anywhere. I would think that the code should be gone after replacing both catalytic converters, and both O2 sensors.
Should I try installing an O2 sensor spacer?
TLDR: Recurring P0420 continuing with new cats and O2 sensors. Computer has been reset, no exhaust leaks found, no driveability issues. What's causing code? How can I turn off for good?
Well they say they replace the engine. If they didn't do a good job, they'll keep tripping the codes for inefficient. Catalytic converters. Just shows you what crap Hyundai is. The engine went bad. Of course that ruin the catalytic converters and they didn't fix that either. I would stay away from those Korean crabs myself
I agree, I don't like Hyundai at all anymore. Regardless, I do plan on keeping this thing until it dies or becomes a money pit. We had only gone with Hyundai because they used to have the best powertrain warranty of 10 years or 100k miles, but it shouldn't be needed, as it was in this case. I tried resetting the computer once again and the code has stayed away for a few drive cycles now. I'm just hoping it will stay away for good. At least it's finally running how it should. If the code comes back though, I think I will try an O2 sensor spacer. I know it's hit or miss with them, but I belive it would be worth a shot.
P.S. I love your videos, Scotty! They are entertaining and have taught me so much!