Question about 1995-1997 Chevy Suburban Ignition Starter Alarm switch

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High CO emissions

My 95 Suburban won''t pass our county emissions for the 1st. time in 14 years for a higher than normal CO output.

Does anyone know what will cause this ?

The readings are as follow:
CO 2500RPM 2.15 The limit is 1.20 FAIL
CO Idle 3.22 The limit is 1.20 FAIL

This is a 454 throttle body type fuel injection
HC 2500RPM 37.8 Limit 220.0
CO2 2500RPM 13.53

HC Idle 121.2 Limit 220.0
CO2 Idle 12.86
EVAP Gas Cap 27.90 In H20 Limit 6.00

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Run the fault codes and look for problem heated oxygen sensor ( HO2S) in the exhaust manifold , or problem oxygen sensor (O2S) after the cat converter, problem EGR system or problem cat converter

Posted on Apr 05, 2017


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