P0420 and P0430 stock exhaust

[jcastellaw]

I'm wondering it my cats are plugged. I have a 2004 Dodge Hemi 3500 and need all the low end pulling power that I can get. Would Hi flow cats help? The Trinity tuner has helped a lot!!!!
Also, thermostat was stuck and I installed a new one. This truck need ps to last 2 more years? Any Ideas would be appreciated. Should I clean the PCV valve? I've read too much! Lol

[mikel]

yes, if you are getting those codes with stock exhaust, I would guess your cats are clogged and replacing them would help quite a bit.

[jcastellaw]

I have the same issue with both a 420 and 430 code. Should we replace with cats or go without based on performance. I have a 3500 5.7 hemi and need all the low end torque possible. Also, where I live, there is no emission test.

[baychef]

im getting the same codes in a 2018 chevy silverado 1500 , had no such problems , until mechanical delete and afm disable , so how do they go bad in one week