Code p0421
Are there other codes set? This code, by itself, P0421 (https://www.yourmechanic.com/article/p0421-obd-ii-trouble-code-warm-up-catalyst-efficiency-below-threshold-bank-1-by-andrew-quinn) indicates that the engine management system detected the catalytic converter is performing below expected standards. This means the engine is sending contaminants (unburned fuel, oil fumes, etc.) down the...