Hello Team
I've been getting a P0430 code (Catalytic Efficiency Below Threshold Bank 2) for the last

few months. However, the car drives and idles fine. It even starts without any issues.

Anyway, I decided to add some Cataclean in and reset the code. After about 300 miles of

driving, the code decides to come back on. I do a little research and many stated that it

could be the 02 sensor, so I replace it, reset the code and do the idle relearn.

The code comes back on after about 200 miles of driving! So I replace the gas cap and

spark plugs. Reset and relearn. But the code continues to haunt me. I've also cleaned the

MAF sensor and checked for leaks

Could my Cat really be going out? The car has no performance issues and idles perfectly

fine. If it really is the Cat, does anyone have any recommendations for a stock aftermarket

one?

Thank you
Car - 05 sedan RevUp. 170k

 

That was a huge issue on the Maximas when I had one. Sometimes a reflash would fix the issue. But mostly it took replacing the cat.

 

Take off the cat and inspect, also smoke check for exhaust leak.

 

Thanks for the replies. It's been a week and the light hasn't came back yet. I just poured gas today and noticed my gas mileage went from 16/17mpg to 18/19mpg after changing my o2 sensor. If it comes back soon, I'll consider a new cat. Any recommendations on OE replacements without breaking the bank?