P0430 code 2016 3.5ecoboost

Hey everyone,

I have a 2016 XLT F150 3.5 EcoBoost 2WD with 117k miles. For about six months now, I’ve been dealing with the P0430 code and the check engine light. Occasionally, the light turns off by itself, and I’ve also reset it a few times with my scan tool.

I’ve already cleaned the airflow sensors and changed the spark plugs. Since it’s a catalytic converter issue, I am considering replacing the O2 sensors or possibly the catalytic converter. I wanted to see if anyone else has had this issue or has any recommendations.

Initially, the light would come on once every month or two, but now it comes back quickly after I reset it. I found a driver’s side direct-fit catalytic converter on Rock Auto for around $230, which seems cheap. Is there any downside to buying a less expensive catalytic converter compared to a pricier one? Any advice would be greatly appreciated!

I had the same engine code on my 2019 3.5L EcoBoost. I tried saving money by buying a cheap aftermarket downpipe, but it was a total waste of time. It didn’t fit properly and leaked. I had to reinstall the original, expensive part.

Before putting the original back on, I checked the catalytic converters and they looked fine. Out of curiosity, I used a fuel system cleaner and O2 sensor extenders. So far, the code hasn’t returned.

Basically, do not bother with cheap aftermarket parts for this issue.

My father-in-law’s Platinum has the same issue and same code.

I am going to start by replacing the spark plugs since they are due, then I will swap the post-cat O2 sensors to see if the problem moves to the other side of the engine. I’m also checking for vacuum leaks and cracks in the turbo manifold. If I had a smoke machine, I’d use it to check for leaks.

I suspect it might be a bad catalytic converter, but I don’t want to just start replacing parts without knowing for sure. Let me know what you find out.

I had a similar issue with my 2015 3.5L EcoBoost, getting those pesky P0420 and P0430 codes every 50 miles. I tried the usual stuff like new spark plugs, cleaning sensors, and a new air filter, but the problem kept coming back.

As a last resort, I bought some cheap spark plug non-foulers and drilled a hole in them. I installed them between the catalytic converter and the O2 sensor. So far, so good. No more codes after 250 miles. It is a super cheap fix compared to replacing the cats, so it might be worth a shot.

Codes P0420 and P0430 are very specific to the catalytic converter’s performance. The rear oxygen sensor, located inside the catalytic converter, measures the exhaust gas cleanliness. The car’s computer compares this reading to the front sensor’s data. If there’s a significant difference, indicating the catalytic converter isn’t working correctly, it triggers the code.

Catalytic converters heat up quickly after startup, then gradually cool down. This process should take less than five minutes. A scanner can show this in real-time.

The car’s computer has complex checks in place, making it difficult to bypass the system. If the code persists, it likely means the catalytic converter’s internal components are damaged or contaminated.

My check engine light kept coming on and off, so I finally replaced the catalytic converter. Instead of buying an expensive OEM part, I opted for a Magnaflow aftermarket one that was supposed to be a direct fit.

Unfortunately, the new catalytic converter was too big to fit properly, so I had to modify it by cutting off a small piece to make it work. Installing the exhaust was a pain, but an impact wrench and a swivel socket were lifesavers.

Hopefully, replacing the catalytic converter will fix the issue.