Ways to clear a P0430 Catalyst code without buying new cat?

[FishFreak]

So last week I had to offload my 5 Star 91 Octane Performance tune, and revert to stock for the bi-annual smog test. Boy what a dog my 6.2 L is when you're used to that sweet tune ! Very noticeable! A few days later, I get a CEL and a P043 fault code for Catalyst System Efficiency Below Threshold on 'bank 2'!

Is it a coincidence with the tune swap? Never threw any codes in nearly 2 years with that tune. I feel like the cat efficiency code may be the symptom and not the problem. Dirty injectors? If EGR sensor, which one? Doesn't it have one before and after the cat? No noticeable changes in running other than tune differences. Truck runs and idles great. Averages 10.5 mpg but I've got a heavy right foot. I'm about to change the plugs, wires, boots and resistors (139k on them now. I bought it with 132k). Anyone else get this and fix it? What else could correct this code without replacing an expensive cat converter? Bottle of parts store magic elixir in the next gas fill-up? I've got a couple months on my Banks CAI with the mesh pre-filter, and it's still clean. I'm in ******-fornia, so I can't get rid of my cats.


I have not checked at night for coil spark leakage but I will. Do I spray water on the coils to see that? Also, is the cylinder number diagram below correct for our 6.2's? Is 'Bank 1' cylinders 1-4 and 'Bank 2' cylinders 5-8?

So many questions !! Thanks IA!!

 

[downforce137]

I'd be looking at the downstream o2 sensors first..

this code means the sensor is reading too much hydrocarbons getting past the cat..

Also, I always take my emissions tests with the tune in there. Usually they're plugging in to check the on board diagnostic system is functioning and has run and passed its own testing.. not doing actual tests, unless you're in CA

 

[FishFreak]

I'd be looking at the downstream o2 sensors first..

this code means the sensor is reading too much hydrocarbons getting past the cat..

Also, I always take my emissions tests with the tune in there. Usually they're plugging in to check the on board diagnostic system is functioning and has run and passed its own testing.. not doing actual tests, unless you're in CA

Thanks, I'll try swapping left/right downstream sensors first and clear the code. I AM in CA. I thought the smog Nazis here might lock me up and take me in for running a tune that's NOT ALLOWED on the left coast!! Do you have smog or are you using the emissions tester to tune AFR?

 

[downforce137]

Thanks, I'll try swapping left/right downstream sensors first and clear the code. I AM in CA. I thought the smog Nazis here might lock me up and take me in for running a tune that's NOT ALLOWED on the left coast!! Do you have smog or are you using the emissions tester to tune AFR?

I'm in the free state of indiana. I pull up to a government run facility, they make sure the check engine light isn't on, check fuel cap, plug in and check obd readiness and tell me to have a nice day.. every other year..

Gen1 had 5 star
Gen2 has goose
And my fusion sport is tuned as well

 

[FishFreak]

They used to stick a tailpipe sensor in and measure your emissions here in CA, but you're right, I think now they just check your obd readiness? Maybe they don't test for ECM software version? I might just flash my 5 Star tune back on and swap 02 sensors.