2001 Nissan Pathfinder, P0430 and P0420, 75,500 miles

[bajasun]

Recently replaced the 02 sensors, bank 1 and 2 with Bosch Universal parts.Also, flushed and cleaned the fuel system.

Now P0430 and P0420 codes are popping up...was it a mistake to use the universal 02 sensors? Should I take them out and replace with genuine Nissan parts at a much greater cost, almolst $500.00 for the two?

Is it the catalytic converters that need to be replaced?

Please advise, thank you very much!

[steve s14]

which sensors did you replace?the primary or the secondary?those codes are cat codes bank one and bank two.your catalytic converters may be bad but i would test them to be sure. monitor the secondary sensor voltage and see if it goes up and down like the primary one does with the engine at operating temperature. if it does, then you most likely have bad cats.if it's pretty steady and doesn't go up and down much, then the cats are working.

[bajasun]

Thank you!!! Both were rear. I'm out of town, actually in Mexico for 3 weeks and will check it out upon my return. Thanks again for the info...I'll get back with you.