high CO emissions
Thread Starter
CF Junior Member
Joined: Jan 2008
Posts: 57
Likes: 0
From: Cleveland, Ohio
high CO emissions
Hello,
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 Idle3.22 The limit is 1.20 FAIL
This is a 454 throttle body type fuel injection
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 Idle3.22 The limit is 1.20 FAIL
This is a 454 throttle body type fuel injection
Thread Starter
CF Junior Member
Joined: Jan 2008
Posts: 57
Likes: 0
From: Cleveland, Ohio
RE: high CO emissions
MDTAHOE,
I have only driven this truck about 3000 miles in the last 2 years. And I replaced the converter then (2yrs. ago) with a aftermarket converter. At that time it was running rich due to a faulty coolant sensor. And NO i do not see anything about NOX.
Thanks, Jack
I have only driven this truck about 3000 miles in the last 2 years. And I replaced the converter then (2yrs. ago) with a aftermarket converter. At that time it was running rich due to a faulty coolant sensor. And NO i do not see anything about NOX.
Thanks, Jack
Thread Starter
CF Junior Member
Joined: Jan 2008
Posts: 57
Likes: 0
From: Cleveland, Ohio
RE: high CO emissions
MDTAHOE,
I spoke with another mechanic today and he said on a vehicle like this the two most common causes would be high fuel pressure or a faulty injector. He said he would check the inlet /outlet temperatures first (they should be 100 degrees difference) if the converter was active? Would you tell me what you think before i go replacing parts I can't already afford ?
Thankyou !
I spoke with another mechanic today and he said on a vehicle like this the two most common causes would be high fuel pressure or a faulty injector. He said he would check the inlet /outlet temperatures first (they should be 100 degrees difference) if the converter was active? Would you tell me what you think before i go replacing parts I can't already afford ?
Thankyou !
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Professional Mechanic
Professional Mechanic
Joined: Nov 2008
Posts: 2,950
Likes: 5
From: Bowie, MD
RE: high CO emissions
CO is a measure of fuel mixture. HC is a measure of unburnt fuel.CO2 is a measure of efficiency anthing over 12.00 is good.If you had a bad injector or high fuel pressure your HC would be extremly high and co2 would be very low. Most things that effect CO should effect other numbers except the converter. You can not check converter function that way all you can check is if it is restricted. You need a shop with a emissions scope to perform a oxygen capture test on the cat. Even though it is new it does not mean it is good. I have had sever aftermarket cats bad out of the box. A bad injector ar high fuel pressure can be proved or dis-proved in less than 10 minutes with a pressure gauge.
