If the oxygen sensor was bad, would it affect my idle??
Jan 20, 2006 at 8:17 AM
GMC Bad Oxygen Sensor Rough Idle
GMC
MJWIDD
- MEMBER
- 12 POSTS
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yes it determines how rich or lean the engine is running, and if not reading properly it will run rough. recomended changes are 25,000-50,000
plus with a good sensor gas milage can increase up to 15% and at the pump that definatly pays for the 02 sensor.
plus with a good sensor gas milage can increase up to 15% and at the pump that definatly pays for the 02 sensor.
Jan 20, 2006 at 8:23 AM
The O2 sensor does not usually work as soon as you start the engine from cold. So the O2 sensor is not in the picture as of yet, the ECM is said to be in open loop. Once the O2 sensor gets hot enough to start producing a voltage the ECM sees this and then goes into closed loop and the O2 sensor controls A/F ratio. Has a lot to do with if you have a 1 wire sensor or a multiple wire (heated sensor) as to how soon it starts working after start up
Darryl...
Darryl...
Jan 23, 2006 at 9:53 AM
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Suggested Repair
A bad oxygen sensor can cause rough idle because it determines whether the engine is running rich or lean. Replace the sensor if it is not reading properly; a commonly cited interval is 25,000 to 50,000 miles. A working sensor may also improve fuel economy.
Conversation Summary
The owner of a GMC asked whether a bad oxygen sensor would affect idle. An expert said yes: an incorrect reading can make the engine run rough, and replacement around 25,000 to 50,000 miles was suggested, with a possible fuel-economy improvement. Another participant added that after a cold start the ECM stays in open loop until the sensor heats and produces voltage, so it does not control the air-fuel ratio until closed loop; heated multi-wire sensors begin working sooner than single-wire sensors.