What Causes A P0420 Code?

What Causes A P0420 Code?

If the front signals and the rear signals look identical, the catalyst isn't doing its job.

A recent EPA study showed that 7% of cars in the United States were operating below federally mandated emissions. Some 68% of those emissions failures were due to P0420 or P0430 catalyst-system inefficiency below threshold OBD 2 code.

This video is sponsored by AP Emissions Technologies.

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