P0420 Diagnostic Trouble Code Discussion for January 2019
Catalyst Efficiency Below Normal (Bank 1)
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| Help Request | Posted | |
| 2007 Honda Civic EX 1.8L MIL Lamp on VIN: 2HGFG12837 P0420: Catalyst Efficiency Below Threshold. I'm trying to understand the patterns on the AF and O2. For starters I'm guessing that the O2 switching is a result of the bad cat. Having seen this I noticed that the AF ma is cycling in the fractional ma range in the opposite direction. For example in th... |
January 18, 2019 |
