P0421 Diagnostic Trouble Code Discussion for February 2016
Warmup Catalyst Efficiency Low (Bank 1)
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| Help Request | Posted | |
| 2006 Jeep Wrangler Sport 4.0L Excessive Emissions, MIL Lamp on VIN: JF4F449S96 P0421: Catalyst Efficiency Below Normal (Bank 1). ... light keeps coming on, it first had the p2098, p2096 down stream fuel trim lean and the po431 catalytic converter codes, found a bulletin for the PCM reflash, we had that done , the light came back on ,replaced the front oxygen sensors, the light came back... |
February 23, 2016 |
