I have a 2020 King Ranch 4WD with a 5.0. Truck has just shy of 110,000 miles. It started throwing the 0430 code around 95,000 miles.

I have done the following:
-new plugs
-new O2 sensors, both fore and aft
new cat (Flowmaster )

I did not see anything unusual in the plugs, they all looked about the same. I do "lose" a little over a quart of oil every 5,000 miles, which Ford says is normal (I call BS on this)

I am continuing to get the code every 300-5oo miles. I am at a loss and hoping someone can give me some ideas.

Thanks guys

 

Here are some suggestions:

1. Not trying to be a jerk, but did you change the cat on the wrong side? P0430 is Bank-2, the Driver Side.
2. How is the rest of the exhaust system? Exhaust leaks is second on the possible causes list and damaged exhaust manifold is number three.
3. Another possible cause is the EVAP purge valve leaking or sticky open.
4. How is the fuel mileage? Leaking injector is another possible cause.

 

I did change the correct CAT - valid question.

Mileage has not moved much, maybe 1 mpg. I have not noticed exhaust leaks but I will definitely look in to that

 

Forscan will tell you how far out the efficiency is on the cat. The aftermarket cats I have are really close but just a little out of range to not pop the 420/430 code. I just use O2 defoulers with the rear O2 sensors.

 

Forscan shows pretty consistent readings across the sensors, when comparing the sensors to the adjacent sensor in the opposite bank.

 

Does it tell you which cylinder is having the issue? There is still the actual coil itself that may be malfunctioning.

 

The cylinders are mapping out just fine. I do not see any variatio0ns when monitoring them.

 

Does anyone see anything out of line here?

 

Not to belabor the point, but was it the driver's or passenger side that was replaced?

 

The only thing I see is it seems odd that both converters are at the exact same temperature, 887°F. I wonder what are the odds of that happening.