P0422 reads : Catalyst System Low Efficiency Bank 1. The rear O2 Sensors compare the data with the front O2 Sensors and have figured out the catalytic converter is no longer doing a efficient job. The most common fix for this problem is to simply replace the Catalytic Converter. There is the off chance the rear O2 Sensor is failing to read correctly.
EMISSIONS WARRANTIES FOR 1995 AND NEWER CARS & TRUCKS
Federally required emission control warranties protect you, the vehicle owner, from the cost of repairs for certain emission related failures that result from manufacturer defects in materials and workmanship or that cause your vehicle to exceed federal emission standards. Manufacturers have been required by federal law to provide emission control coverage for vehicles since 1972. There are two federal emission control warranties discussed in this fact sheet: (A) "Performance Warranty" and (B) "Design and Defect Warranty". This fact sheet explains each warranty in detail, provides you with a list of some of the parts covered under these warranties, explains the procedures for making an emissions warranty claim, and answers some of the most commonly asked questions about emissions warranties. Finally, we will give you some tips on how to prevent future emission-related failures and maintain the longevity of your vehicle's engine
. A. PERFORMANCE WARRANTY The Performance Warranty covers repairs which are required during the first 2 years or 24,000 miles of vehicle use because the vehicle failed an emission test. Specified major emission control components are covered for the first 8 years or 80,000 miles. If you are a resident of an area with an Inspection and Maintenance (I/M) program that meets federal guidelines, you are eligible for this warranty protection provided that:
* Your car or light-duty truck fails an approved emissions test; and
* Your vehicle is less than 2 years old and has less than 24,000 miles (up to 8 years/80,000 miles for certain components); and
* Your state or local government requires that you repair the vehicle; and
* The test failure does not result from misuse of the vehicle or a failure to follow the manufacturers' written maintenance instructions; and
* You present the vehicle to a warranty-authorized manufacturer representative, along with evidence of the emission test failure, during the warranty period. During the first 2 years/24,000 miles, the Performance Warranty covers any repair or adjustment which is necessary to make your vehicle pass an approved, locally-required emission test and as long as your vehicle has not exceeded the warranty time or mileage limitations and has been properly maintained according to the manufacturer's specifications.
Reference Link : https://www.epa.gov/otaq/consumer/warr95fs.txt