Emissions Issue
 

My son bought his first car entirely on his own. The next day the 2013 Mustang with a six cylinder throws a code for a possible MAF issue. He replaced the MAF and all is well. The second day, it throws the code for the converter. My concern is, do we have an issue causing these codes and replacing the MAF and converter will not solve the bigger issue. Any suggestions? Thank you.

Sounds Like Things are a Bit Gummed Up From What You Say! I Would Start Out With Some Good Fuel Additive Like Chevron Techron. Let The Car Run Down To about 1/8 Tank Put in Additive with a Tank of High Test in Case The Fuel is Contaminated. Take it For Nice Highway Run of a Hundred Miles or So and See if Things Improve. I Would Not Replace Converter Yet and Post The Code Numbers You are Getting. I Have Listed the Dtc codes in Service & Repair & Also There is a Diag Section.

Meanwhile Some More Info Such as Vehicle History and Mileage Would Be Helpful! Was This Someones Weekend Car and Sat a Lot or a Daily Driver. Just As Much Background as Possible. Send Me The VIN via Pm & I Will See if I Can Find any FORD History Online For The Car which May Shed Some Light. Pictures of The Car To Determine What Kind of Care Was Given To The Car Would Be Useful. Need To See A Good Overall Picture Set Like an Online Car Ad Uses!

https://themustangsource.com/forums/...e-info-550475/

Anyhoo That's My Suggestion!

Mgb,

KC

Code P0420.

The car was bought used from a dealership with 110,000 miles.

P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
Description: This DTC sets when the bank 1 catalyst system efficiency is below the acceptable threshold.
Possible
Causes: Damaged heated oxygen sensor (HO2S)
Exhaust leaks
Damaged exhaust manifold
Damaged catalytic converter
Oil contamination
Cylinder misfiring
Downstream HO2S wires incorrectly connected
Damaged exhaust system pipe
Damaged muffler and tailpipe assembly
Leaking fuel injector
Oil contamination of the catalyst
Damaged turbocharger
Base engine concerns
Diagnostic
Aids:
Under normal closed loop fuel conditions, high efficiency catalysts have oxygen storage which reduces the frequency
and amplitude of the downstream HO2S. As catalyst efficiency deteriorates, its ability to store oxygen declines and the
downstream HO2S signal has an increased amplitude and frequency. The PCM compares the signal line length of the
downstream HO2S to an expected signal line length of the downstream HO2S with a deteriorated catalytic converter.
Diagnose any base engine concerns. Refer to the Workshop Manual Section 303-00, Engine System.
Application Key On Engine Off Key On Engine Running Continuous Memory
All GO to Pinpoint Test HF See Pdf Diag.


Added Some Pdf's To Help!

With a Vin I Can See if Car Had Warranty Issues in the Past! Such as Emission Issues Etc.

KC

first, welcome to the forum

a lot of these issues are often due to modifications made by prior owner

MAF issues could be due to the installation of an aftermarket intake, aka "CAI" -- does the car have the factory air box and intake tube?

"catalyst efficiency" codes could be due to removal of the catalytic converters -- does the car have the original exhaust with cats, or have the cats been removed?

also, do you know if the car has an aftermarket custom "tune" installed? often the modifications have "tune" adjustments to go with them; and if not done correctly, that can cause some issues