Hard shut off on 4.1l engine - The 1947 - Present Chevrolet & GMC Truck Message Board Network

kcabbie · 02-20-2011, 01:36 AM

Okay, well i just ordered a new o2 sensor! Hopefully that will fix it up. It was rated 25 hw mpg. It's only getting about fifteen. Even if it's not going to get the whole 25,, which i understand,, it should get ALOT better than it does.
So did i make a good call on getting the new sensor?
Thanks again for all the help.

1LowToy · 02-20-2011, 11:36 AM

As I recall the O2 sensor detects oxygen in the exhaust and creates voltage. The higher the voltage output of the sensor the lower the duty cycle will be to the carb to richen the mixture. The other thing is a water temerature sensor to tell the computer that the engine is warm enough to start functioning or go into what they call closed loop (Closed loop computer taking charge of the engine fuel management).

See if Autozone has a diagnostic for the O2 sensor.

25 MPG is a high estimate, and may include wind at your back. What transmission do you have? Rear axle ratio? (that may be listed on the equipment list on you glovebox door.

02-20-2011, 01:36 AM	#1
kcabbie Registered User Join Date: Jan 2011 Location: houston texas Posts: 64	Re: Hard shut off on 4.1l engine Okay, well i just ordered a new o2 sensor! Hopefully that will fix it up. It was rated 25 hw mpg. It's only getting about fifteen. Even if it's not going to get the whole 25,, which i understand,, it should get ALOT better than it does. So did i make a good call on getting the new sensor? Thanks again for all the help.

02-20-2011, 11:36 AM	#2
1LowToy Registered User Join Date: Nov 2009 Location: Sonora California Posts: 860	Re: Hard shut off on 4.1l engine As I recall the O2 sensor detects oxygen in the exhaust and creates voltage. The higher the voltage output of the sensor the lower the duty cycle will be to the carb to richen the mixture. The other thing is a water temerature sensor to tell the computer that the engine is warm enough to start functioning or go into what they call closed loop (Closed loop computer taking charge of the engine fuel management). See if Autozone has a diagnostic for the O2 sensor. 25 MPG is a high estimate, and may include wind at your back. What transmission do you have? Rear axle ratio? (that may be listed on the equipment list on you glovebox door.



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