# p0420 reoccuring



## kevins7189 (Oct 2, 2017)

same issue here, did you ever get it resolved?


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## staticcase (Oct 24, 2017)

mamom2012 said:


> I have a 2014 Chevrolet Cruze LTZ. Its the 1.4L turbo. It has recently thrown me the P0420 code. I had the cat converter replaced at a mechanics shop due to I am over the 80,000 miles for it to be covered under warranty. Not even 3 hours later after picking it back up the check engine light comes back on. Take the car to Autozone and the diagnose it with the Same code again. I contact the mechanic and they have me bring it back to them. They look at it and everything looks and seems fine on the car. They went ahead and ordered another converter incase the one they put on had a defect in it. I took the car in Wednesday and they put the converter on again for the 2nd time. Everything seemed fine and the car was driving like brand new again. I was hopeful it was fixed. Sad to say yesterday evening the dreaded check engine light is back on. I took it back to AutoZone last night and once again for the 3rd time in a week, its the P0420 code!!


I am having the same exact issue. I just bought two O2 sensors since I know those cats don't usually go bad under 125K. But anyway, they were cheaper too... So have either of you had luck in fixing the problem yet?


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## BobFord (Mar 1, 2020)

Just bought this car for wife and have same code any thoughts?I'm thinking first sensor before cat because of the fuel ratio being off?
BTW Im having mixed thoughts about the car just had the turbo manifold just replaced at 135k bought it used from dealership
2014 1.4l turbo other than little **** car runs good


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## Blasirl (Mar 31, 2015)

BobFord said:


> Just bought this car for wife and have same code any thoughts?I'm thinking first sensor before cat because of the fuel ratio being off?
> BTW Im having mixed thoughts about the car just had the turbo manifold just replaced at 135k bought it used from dealership
> 2014 1.4l turbo other than little **** car runs good


Welcome Aboard!

A code *P0420* may mean that one or more of the following has happened: 

Leaded fuel was used where unleaded was called for (unlikely) 
A damaged or failed oxygen / O2 sensor 
Downstream oxygen sensor (HO2S) wiring damaged or connected improperly 
The engine coolant temperature sensor is not working properly 
Damaged or leaking exhaust manifold / catalytic converter / muffler / exhaust pipe 
Failed or underperforming catalytic converter (likely) 
Retarded spark timing 
The oxygen sensors in front and behind the converter are reporting too similar of readings 
Leaking fuel injector or high fuel pressure 
Cylinder misfire Oil contamination
Read more at: P0420 Catalyst System Efficiency Below Threshold

Don't forget to introduce yourself and your Cruze here.


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## January (Oct 2, 2019)

mamom2012 said:


> I have a 2014 Chevrolet Cruze LTZ. Its the 1.4L turbo. It has recently thrown me the P0420 code. I had the cat converter replaced at a mechanics shop due to I am over the 80,000 miles for it to be covered under warranty. Not even 3 hours later after picking it back up the check engine light comes back on. Take the car to Autozone and the diagnose it with the Same code again. I contact the mechanic and they have me bring it back to them. They look at it and everything looks and seems fine on the car. They went ahead and ordered another converter incase the one they put on had a defect in it. I took the car in Wednesday and they put the converter on again for the 2nd time. Everything seemed fine and the car was driving like brand new again. I was hopeful it was fixed. Sad to say yesterday evening the dreaded check engine light is back on. I took it back to AutoZone last night and once again for the 3rd time in a week, its the P0420 code!!


Did you ever get this resolved?


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