2016 Ford F-150 P0430

[Jim Oaks]

Today I noticed that my check engine light was on in my 2016 F-150 with the 3.5 Ecoboost. Truck runs fine and when I got home I scanned it and got a P0430 code.

"Catalyst System Efficiency Below Threshold (Bank 2)."

From what I've read, this is usually a bad converter, not a bad O2 sensor.

Anyone have any experience with this?

I'm thinking my girlfriend had this converter code on her Jeep, and we got rid of it by pouring a catalytic converter cleaner in the gas tank.

I can't possibly get that lucky.

 

[Mechrick]

Cat efficiency codes can be a pain.
I scanned the chart for that code, it has you checking fuel pressure, for exhaust leaks, exhaust back pressure, etc. Never mentions sensors except for checking the fuel rail pressure sensor for bias.

Has it started using oil?

From the verbiage of the chart, there are monitored and unmonitored converters. The converter sandwiched between the upstream and downstream sensors on bank 2 is the culprit.

I would try the cleaner, can't hurt. Also, if the bank 1 and bank 2 sensors are the same part numbers, I would swap them both left to right, clear codes and drive it. It's possible for an upstream or downstream sensor to bias rich or lean, which can cause P0420/P0430 codes (very rare). If the code moves to bank 1 suspect a biased sensor. Usually this will trip additional codes however.

What causes the cat efficiency codes to trip is when the downstream sensor mirrors the upstream sensor when running conditions should cause the downstream sensor to stay lean. In other words, when the engine is in closed loop and the upstream sensor is switching rich/lean, converter is warm, at that point the converter substrate should be removing hydrocarbons from the exhaust to the point that the downstream sensor lays dead lean. Compromised substrate causes the sensor to switch when it shouldn't.

The PCM will occasionally throw it a rich mixture expecting it to switch rich just to make sure it's still plugged in...

 

[Jim Oaks]

Weird.

I filled the truck up with gas and the check engine light went out. I've driven well over 300 miles and a full tank of gas and the check engine light hasn't came back on.

 

[scotts90ranger]

Cat efficiency codes aren't perfect, it's possible the test happened at the exact wrong time, plus it doesn't always do the test...