[GlennB12]

Hello,
I got a P0430 code on my 2021 LT1.

Says I should replace the catalytic converter.

If I purchase a new catalytic converter from GM, would I have to tune the car? I saw somewhere online that some cars need a tune after a cat replacement and wasn’t sure if I could just replace and break it in and drive normally. Just got the car and only have about 16k miles on it.

I have ordered a O2 sensor, but I am going to swap the stock sensors to trouble shoot and see if the code goes to the bank 1 side to see if possibly the sensor went bad. Still new to this stuff so forgive me if I sound amateur about this. Just trying to get some advice on how to get rid of this engine code before emissions.

Any input would be greatly appreciated!
Thank you.

[Joshinator99]

Originally Posted by GlennB12

Hello,
I got a P0430 code on my 2021 LT1.

Says I should replace the catalytic converter.

If I purchase a new catalytic converter from GM, would I have to tune the car? I saw somewhere online that some cars need a tune after a cat replacement and wasn’t sure if I could just replace and break it in and drive normally. Just got the car and only have about 16k miles on it.

I have ordered a O2 sensor, but I am going to swap the stock sensors to trouble shoot and see if the code goes to the bank 1 side to see if possibly the sensor went bad. Still new to this stuff so forgive me if I sound amateur about this. Just trying to get some advice on how to get rid of this engine code before emissions.

Any input would be greatly appreciated!
Thank you.

Is the car completely stock…?

[GlennB12]

Only thing that the car has is a muffler delete.

[dfwcowboy]

Could it potentially have an exhaust leak? Fuel efficiency normal?

[Joshinator99]

Originally Posted by GlennB12

Only thing that the car has is a muffler delete.

Originally Posted by dfwcowboy

Could it potentially have an exhaust leak? Fuel efficiency normal?

Exhaust leak is a prime reason, and the most common one, for that code to pop up.

[GlennB12]

I took it back to the exhaust shop and they did a full exhaust leak check and they couldn’t find any leaks.

[Joshinator99]

Originally Posted by GlennB12

I took it back to the exhaust shop and they did a full exhaust leak check and they couldn’t find any leaks.

You can try replacing the sensor, but I find it odd a 2 year old car would have a bad O2 sensor or cat…

[GlennB12]

Same, I’ll try a different exhaust shop then and see if they find a leak anywhere.

[ctrlz]

If this is only code you are getting, then exhaust leak on bank 2 (which I believe is driver's side) is likely. Bad O2 sensor or bad converter both unlikely.
swapping o2 sensors and/or hooking up a scan tool can help confirm the problem.
"Exhaust leak" is a bit misleading here, because problem is not really exhaust getting out, but oxygen getting into the exhaust stream. The sensor is picking up more residual o2 than expected. This can be due to leak before or around that sensor, or damage to the sensor.

[KingLT1]

bank 2 is on the passenger side with all generation small block chevy's.

[Mark114]

Originally Posted by GlennB12

Hello,
I got a P0430 code on my 2021 LT1.

Says I should replace the catalytic converter.

If I purchase a new catalytic converter from GM, would I have to tune the car? I saw somewhere online that some cars need a tune after a cat replacement and wasn’t sure if I could just replace and break it in and drive normally. Just got the car and only have about 16k miles on it.

Originally Posted by Joshinator99

Is the car completely stock…?

Originally Posted by GlennB12

Only thing that the car has is a muffler delete.

The car could still be covered by the drivetrain and emissions warranty if they don’t try to blame the muffler delete. You might want to check with a Chevy dealership before spending more of your own money on it.

[ctrlz]

Originally Posted by Mark114

The car could still be covered by the drivetrain and emissions warranty if they don’t try to blame the muffler delete.

Thanks for the correction on bank 2.
Dealer will say it is O2 sensor related which is a wear and tear item not covered under warranty.
Now the converter, should it prove defective, would be covered. this is very unlikely.
OP is in AZ, so no special added california coverage.

[GlennB12]

Upon doing a leak check on the exhaust I did indeed find a hole! I put high heat JB weld on the hole (says it can withstand 1000 degrees, and is made for exhausts) it takes 24 hours to cure so just waiting on that and will update when I clear the code to see if it comes back.

[GlennB12]

All FIXED ! thank y’all for the advice!