P0420 Diagnostic Trouble Code Discussion for September 2019
Catalyst Efficiency Below Normal (Bank 1)
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| Help Request | Posted | |
| 2003 Chevrolet S10 4.3L Poor Idle Quality VIN: 1GCCS19X73 P0420: Catalyst System Low Efficiency. Hi, need some new ideas or insights. This engine idles rough. Has a definite stumble. I've done the testing below as well as isolating the fan clutch/accessories, testing AC voltage, cleaned IAC and t-body, and pressure drop tested all injectors (good; 16 ... |
September 17, 2019 |
