OBD-II Code Decoder

P0421 — vehicles with official records naming this code

P0421 is named in NHTSA-published manufacturer communications or investigations for 9 vehicle families, including:

• Mazda Mazda6 model years 2014-2016 · 6 records
• Mazda CX-5 model years 2014-2016 · 5 records
• Mazda Mazda3 model years 2014-2015 · 4 records
• Mitsubishi Eclipse model years 2006-2008 · 3 records
• Mitsubishi Galant model years 2006-2008 · 3 records
• Chevrolet Cruze model years 2017 · 2 records
• Chevrolet Equinox model years 2018 · 2 records
• GMC Terrain model years 2018 · 2 records
• Mazda MX-6 model years 1996-1997 · 2 records

A code named in a manufacturer communication means the document refers to it for those vehicles. It is not a diagnosis of any car, and it does not mean the code is common on that vehicle.