Code result
P0422
Main Catalyst Efficiency Below Threshold
Moderate severity
What it means
Generic main catalyst efficiency code on bank 1 — used by some manufacturers in addition to or instead of P0420. Indicates the same root cause — degraded oxygen storage in the main catalyst.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Catalyst aged or contaminated
highOne of the most commonly reported causes for this code — check this first.
Oxygen sensor drift
mediumA plausible cause — test and verify before replacing parts.
Related help
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