How to pinpoint the problem of P0420 code on a tacoma 2006.

Question

I have a tacoma 2006 Alternator and battery died then explosions were heard as I step on the gas then the car died after the alternator got replaced. P0420 shows short trim for bank 1 sensor 2 is not available to compare on my scanner. How do I pin point my problem?

Answer 1

P0420 Catalyst system efficiency below threshold (Bank1)

On the scan tool use the reading of the 02 sensor . Bank 1 sensor 2. Do a MAF airflow cleaning with a throttle body cleaning , P0420 may have been pending prior to the alernator going out.