Smog fails

1991 JEEP CHEROKEE
227,000 MILES • 4.0L • 6 CYL • 2WD • AUTOMATIC
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DAVELEE575
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co 2.20%---- greater than 1.20%.
Also the tester say he saw smoke from tail-pipe! I did not see it!
Mar 4, 2020 at 12:13 PM
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AL514
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Hello thanks for using 2CarPros, the oxygen sensors and fuel trims need to be looked at on a live data stream. A stuck/failing oxygen sensor or a failing catalytic converter can cause higher CO readings. A stuck oxygen sensor will trick the ECM into going rich and possibly damaging the catalytic converter.
Mar 4, 2020 at 12:36 PM