I have been code free since replacing all four 02 sensors with Denso’s maybe three years ago. Couple weeks ago I accelerated fairly hard and a P0430 code popped up. Scanner showed Bank 2.
Drove a couple weeks and yesterday accelerated medium hard and came back. Hooked up iCarsoft i930 and checked trims.At least at idle after driving 5 - 6 miles everything looks fine. Bank 1 & 2 read the same.
Car is 16 years old and 120K yesterday. Plugs have less than 20k.Cleaned MAF about same time as O2 sensor replacement. Is throwing code after pushing it a sign the CAT’s are going?
Is there a gas tank rejuvenator? I usually run a can of Techron through right before every oil change.

 

My car has about 125k miles (205K Km) and has been giving P0420 and P0430 codes every few days ever since I got it about two years ago. Just before some major work at the end of last year (supercharger replacement) I fitted extenders to the downstream oxygen sensors. I fitted the supercharger and went straight into a 2000 mile road trip lasting over two weeks. I had no problems with the supercharger, but best of all, I have had no engine check lights at all.
I ordered my extenders from AliExpress, but where you are there will be a company doing something similar.
I initially ordered the straight extenders, but there isn't enough space. The right angle extenders have a small honeycomb insert close to the catalyst so this may also help eliminate the errors.
Pete M


Installed

 

@Pete M - Can you post the link where you purchased? It's hard to get hold of the exact part on AliExpress.

 

Hi nsubbu8854,
The original seller that I used does not have that now, but I did find the same thing at these locations:
1005004039044743
0r 33001856782
Just enter the number at the search bar.

Pete M

 

Ordered the first one
https://www.aliexpress.us/item/32568...andl_shipto=US