Last reported case: 1 months ago
Based on 3 owner reports (3 from Reddit)
What is P0420?
P0420 indicates your catalytic converter is not cleaning exhaust gases effectively, typically triggered by a failing converter or upstream engine issues. This powertrain code is moderately serious and can affect emissions and performance, with Honda vehicles like the Accord and CR-V appearing most frequently in reports. Based on 975 repair cases, the average repair cost is $3847, ranging from $0 to $4700.
Common Causes:
- Failing catalytic converter (most common cause based on code definition)
- Upstream oxygen sensor malfunction
- Exhaust leaks before the catalytic converter
- Engine misfires or rich/lean fuel mixture affecting converter efficiency
Symptoms:
- Check Engine Light illuminated (primary symptom)
- Reduced fuel economy reported by some owners
- Possible lack of power during acceleration
- No noticeable symptoms in some cases beyond the warning light
🚗P0420 on 2015 FORD F-150
This page focuses specifically on P0420 issues reported by 2015 FORD F-150 owners. The experiences and fixes below are from real owners of this exact vehicle.
Symptoms Reported by 2015 FORD F-150 Owners:
Parts Often Involved:
What Owners Say
Real experiences from 2015 FORD F-150 owners
“Finally fixed my P0420 catalyst efficiency below threshold code! I have a 2018 F-150 3.5 EcoBoost with 85,000 miles.”View original
“2018 F-150 P0420 Code - What fixed it for me Finally fixed my P0420 catalyst efficiency below threshold code!”View original
“Code came back after 50 miles. Then I cleaned the MAF sensor with CRC MAF cleaner - no luck, still getting the code.”View original
“Ended up being the catalytic converter, $800 at the dealer. Fixed the problem though.”View original
“Fixed the problem though. Lesson learned - start with the cat on P0420.”View original
“Replaced O2 sensor bank 2 sensor 2 - still there. Ended up being the catalytic converter, $800 at the dealer.”View original
“2015 F150 3.5 Ecoboost P0420 P0430 I have a 3.5 ecoboost 155k, it threw a P0420, I reset the code and drove for about 60 miles and then it threw an 0420 and an 0430.”View original
“I have a 3.5 ecoboost 155k, it threw a P0420, I reset the code and drove for about 60 miles and then it threw an 0420 and an 0430. Truck doesn’t appear to have any vacuum leaks or exhaust leaks.”View original
These are real experiences shared by 2015 FORD F-150 owners on automotive forums and communities. Results may vary based on vehicle condition and repair quality.
About This Data
This page aggregates 3 discussions about P0420 from 2015 FORD F-150 owners across automotive communities.
Success rate (67%) is calculated from posts where owners confirmed whether their fix resolved the issue.
Last updated: 1/13/2026