VEHICLE-SPECIFIC TROUBLE CODE GUIDE
P0420 — 2016 Chevrolet Silverado
P0420 on the 2016 Chevrolet Silverado: meaning, symptoms, diagnostic order and repair-cost planning before replacing a catalytic converter.
What P0420 means for this vehicle
The engine computer detected lower-than-expected oxygen-storage performance from the bank 1 catalytic converter. The code measures system performance; it does not prove which component failed.
What to check first
Save all codes and freeze-frame data. Resolve active misfire and fuel-trim codes first, inspect for exhaust leaks, and compare upstream and downstream oxygen-sensor activity under the manufacturer’s specified test conditions.
Avoid an unnecessary converter replacement
Do not order a catalytic converter or oxygen sensor from P0420 alone. Confirm the exact engine, bank location, emissions specification and failed test. Correct an upstream engine problem before installing a converter.
P0420 · 2016 Chevrolet Silverado · Engine, trim, drivetrain and emissions configuration must be confirmed.
Diagnose P0420 for this vehicle