I drive a 2020 Kia Niro hybrid with about 105,000 miles. Loved this car, but now my check engine light came on. They’re saying I need to replace the catalytic converter and O2 sensors for over $7000.
Has anyone else dealt with something like this? I tried calling Kia to say a car just barely out of warranty shouldn’t need such a costly repair, but they didn’t help. I’m so disappointed and honestly wondering if I’d ever buy another Kia again.
You might try asking the warranty admin to reach out to Kia for support since it’s so close to the warranty period. Sometimes, they’ll help cover part of the repair costs—could be as much as 95%.
NaTasha Williams said:
You might try asking the warranty admin to reach out to Kia for support since it’s so close to the warranty period. Sometimes, they’ll help cover part of the repair costs—could be as much as 95%.
Yeah, definitely second this advice, especially if you’ve kept up with maintenance. This is what happened with my transmission repair .
Had the same issue myself. The heat exchanger went bad last year, which led to my cat converter going bad too because of coolant leaks. Super frustrated that Kia hasn’t done a recall, even though lots of people have had this issue.
@MohaveMaverick
Honestly, I haven’t seen a ton of cases. A few, but I wouldn’t say it’s the majority of owners.
vincent said:
@MohaveMaverick
Honestly, I haven’t seen a ton of cases. A few, but I wouldn’t say it’s the majority of owners.
Maybe not the majority, but there are a lot of reports about this on the Kia Niro forums. Tons of owners with early models have had this issue. It’s pretty easy to find info about the heat exchanger workaround online. Given that they’ve sold under 30k Niros each year in the US, I’d say a good number of higher-mileage cars have been affected.
@MohaveMaverick
So what’s the workaround for the heat exchanger? Are they just bypassing it? And what’s the heat exchanger for exactly?
vincent said:
@MohaveMaverick
So what’s the workaround for the heat exchanger? Are they just bypassing it? And what’s the heat exchanger for exactly?
There’s a coolant path around the cat converter to help heat the engine faster in cold weather. Once the coolant gets to a certain temp, it stops flowing around the cat. In hybrids, this system keeps the engine warm when it’s running intermittently. But as it heats up, the coolant turns corrosive and can start leaking into the exhaust, which leads to overheating. Instead of replacing the whole exhaust line, some people disconnect the hoses and re-route them to bypass the exchanger.
I had the fix done myself after hitting 100k (mine’s out of warranty, sadly), and it’s been fine since, though my fuel efficiency drops a bit in winter.
@Miltan
Most helpful comment! I have a 2020 with 50k miles, so I might look into this bypass option.
vincent said:
@Miltan
Most helpful comment! I have a 2020 with 50k miles, so I might look into this bypass option.
It might not be necessary with newer models. Mine’s a 2017, so just keep an eye on your coolant levels. If you see white smoke or notice coolant disappearing, that’s when you’d need to consider the bypass.
vincent said:
@MohaveMaverick
So what’s the workaround for the heat exchanger? Are they just bypassing it? And what’s the heat exchanger for exactly?
Yeah, it’s bypassing the exchanger. It’s supposed to improve efficiency a bit, but honestly, I haven’t seen much difference since I bypassed mine. Runs fine once warmed up.
Sounds like the heat exchanger dumped coolant into your converter. If you don’t fix that, the $7k repair won’t solve your issue.
Same situation here! My check engine light started showing around 85k but went off during cooler months. Now at 115k it’s back. Check with your dealer, even if it’s out of warranty—my transmission was covered except for labour, which saved me big time. If Kia won’t help, I might order a replacement part myself and get a local mechanic to install it.
@Zacky
Watch your engine temp and coolant levels closely. If you’re driving with low coolant, it’ll eventually ruin your engine. Consider bypassing the coolant loop; a mechanic who knows hybrids can help.
I’d be cautious about paying $7k—have a local mechanic bypass the heat exchanger and replace the O2 sensor first. That price is outrageous.
Might be worth checking with an independent mechanic for a second opinion, especially if Kia can’t help.
This was never gonna be covered by warranty—it’s not part of the powertrain.
Try using a catalytic converter cleaner.
Does anyone know if this is covered under the Federal Emissions warranty or the Powertrain warranty? I’m getting the same converter or O2 sensor error, but I’m still under 80k miles. Dealer appointment coming up on Friday… hoping it’s not $7k to fix.