P0136 o2 sensor and Cat Problem

My catalytic converter was stolen maybe 6 mos ago, so I had it replaced with an aftermarket from a muffler shop. Check engine light came on maybe a week later with P0136 bank 1 sensor 2 code.Finally changed it and cleared the code, and now it’s back on after 1 day of driving.
would changing bank 1 sensor 1 fix the issue? Or could it be the aftermarket cat?
Any advice is appreciated.

 

There have been a plethora of comments around here about aftermarket cats consistently throwing codes.

But beyond that, there are plenty of stories about aftermarket O2 sensors throwing codes, AND failure to replace both O2 on the same bank when 1 fails causing codes. O2 sensors are one of those things you want to replace in pairs (before/after cat) and always use OEM.

Some of the cats that others here have reported as not tossing codes include:

• Summit Racing performance
• Magnaflow
• Walker

It would be interesting to know what brand of cat and what brand of O2 the shop put on the truck.

 

Thank you for the reply!
I will replace sensor 1 and hope that resolves it.
I used Denso for the sensor.
I need to find out what cat they put on. I did not even realize they used aftermarket but it now makes sense due to the price and speed of the repair.

 

I would probably bring it back to whomever installed it. I’m guessing it should have been CARB compliant for all 50 states like the OEM Cat.

 

Definitely - whether due to popularity of theft or supply chain issues, OEM cats are not only 3x-6x more than aftermarket, but lead times are several months out right now.

 

More palladium = more $$$ and higher quality CAT like the OEM

 

Hmmm... what if the cat manuf'ers are actually who's buying stolen cats from the fencing operations that buy them from the thieves, and this is all one vicious cycle?

 

I blame McAfee for starting that business model with their development of both virus and anti-virus software.