emission test result
Thread Starter
Cruising
Joined: May 2010
Posts: 12
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emission test result
Have a 1987. Failed emission test category CO (%). High Speed
Standard 0.97) current: 1.17). Low speed: Standard 0.88) current 1.47). Have not had problems passing the annual test previously. Anyone have any ideas on what this could cause this result? Will take it to a mechanic next week. Thanks as always.
Standard 0.97) current: 1.17). Low speed: Standard 0.88) current 1.47). Have not had problems passing the annual test previously. Anyone have any ideas on what this could cause this result? Will take it to a mechanic next week. Thanks as always.
Corvette Enthusiast
Joined: Oct 2007
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From: So. Cal.
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Have a 1987. Failed emission test category CO (%). High SpeedStandard 0.97) current: 1.17). Low speed: Standard 0.88) current 1.47). Have not had problems passing the annual test previously. Anyone have any ideas on what this could cause this result? Will take it to a mechanic next week. Thanks as always.
Standard 0.97) current: 1.17). Low speed: Standard 0.88) current 1.47). Have not had problems passing the annual test previously. Anyone have any ideas on what this could cause this result? Will take it to a mechanic next week. Thanks as always.Good luck
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
High Carbon Monoxide (CO) readings usually indicate a fuel mixture richer than ideal (rich mixture - air fuel ratio below 14.7). In general CO is an indicator of combustion efficiency. The amount of CO in a vehicle’s exhaust is directly related to its air-fuel ratio. High CO levels result from inadequate O2 supply needed for complete combustion. This is caused by a too rich mixture - too much fuel or not enough air (AFR readings below the optimal 14.7, Lambda below 1.0). Circumstances that can lead to high CO emissions:
* Low idle speed
* Improper float settings in carbureted vehicles
* Dirty or restricted air filters
*Excessively dirty or contaminated oil
*Saturated charcoal canister
*Non-functioning PCV valve system
*Improper operation of the fuel delivery system
*Improperly functioning thermactor system
*Catalytic converter intervention and CO concentrations
Hope this gives you some ideas.
* Low idle speed
* Improper float settings in carbureted vehicles
* Dirty or restricted air filters
*Excessively dirty or contaminated oil
*Saturated charcoal canister
*Non-functioning PCV valve system
*Improper operation of the fuel delivery system
*Improperly functioning thermactor system
*Catalytic converter intervention and CO concentrations
Hope this gives you some ideas.
