02 sensor going bad?
08-15-2009 | 03:35 PM
#1
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02 sensor going bad? My car at a dead stand still will studder then go. I had a buddy come over today who has been around these cars for a long time, and he said it feels like my 02 sensor is going bad. It also shakes a little when you are sitting dead still. Please help TIA
08-15-2009 | 09:28 PM
#4
No offense, but it sounds to me like your buddy doesn't know how an O2 sensor works.
You're really not going to "feel" an O2 sensor going bad. O2 sensors measure the amount of oxygen content in the exhaust and report it back to the PCM, which will adjust the A/F ratio in both short term and long term trim to compensate. If the O2 reads lean, the computer will richen the mixture so the O2 goes rich, then it will lean the mixture to compensate and the O2 will go back to lean. It does this many times per second, which basically gives it an average of the A/F ratio. These measurments determine the short term fuel trims, and then the long term fuel trims are based on those numbers.
If the O2 hangs at rich or hangs at lean when the computer commands one or the other, it will set a code and typically stay in open loop, since it can't trust the O2 for accurate readings. So if you have a code for an O2 sensor malfunction, chances are the car is staying in open loop, meaning it should be driving just fine except for decreased fuel economy. Its unlikely that a failed O2 sensor would result in the car stuttering on a start, sounds like another issue. Pull the codes and let us know what you come up with.
You're really not going to "feel" an O2 sensor going bad. O2 sensors measure the amount of oxygen content in the exhaust and report it back to the PCM, which will adjust the A/F ratio in both short term and long term trim to compensate. If the O2 reads lean, the computer will richen the mixture so the O2 goes rich, then it will lean the mixture to compensate and the O2 will go back to lean. It does this many times per second, which basically gives it an average of the A/F ratio. These measurments determine the short term fuel trims, and then the long term fuel trims are based on those numbers.
If the O2 hangs at rich or hangs at lean when the computer commands one or the other, it will set a code and typically stay in open loop, since it can't trust the O2 for accurate readings. So if you have a code for an O2 sensor malfunction, chances are the car is staying in open loop, meaning it should be driving just fine except for decreased fuel economy. Its unlikely that a failed O2 sensor would result in the car stuttering on a start, sounds like another issue. Pull the codes and let us know what you come up with.
08-20-2009 | 10:06 AM
#6
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No offense, but it sounds to me like your buddy doesn't know how an O2 sensor works.
You're really not going to "feel" an O2 sensor going bad. O2 sensors measure the amount of oxygen content in the exhaust and report it back to the PCM, which will adjust the A/F ratio in both short term and long term trim to compensate. If the O2 reads lean, the computer will richen the mixture so the O2 goes rich, then it will lean the mixture to compensate and the O2 will go back to lean. It does this many times per second, which basically gives it an average of the A/F ratio. These measurments determine the short term fuel trims, and then the long term fuel trims are based on those numbers.
If the O2 hangs at rich or hangs at lean when the computer commands one or the other, it will set a code and typically stay in open loop, since it can't trust the O2 for accurate readings. So if you have a code for an O2 sensor malfunction, chances are the car is staying in open loop, meaning it should be driving just fine except for decreased fuel economy. Its unlikely that a failed O2 sensor would result in the car stuttering on a start, sounds like another issue. Pull the codes and let us know what you come up with.
You're really not going to "feel" an O2 sensor going bad. O2 sensors measure the amount of oxygen content in the exhaust and report it back to the PCM, which will adjust the A/F ratio in both short term and long term trim to compensate. If the O2 reads lean, the computer will richen the mixture so the O2 goes rich, then it will lean the mixture to compensate and the O2 will go back to lean. It does this many times per second, which basically gives it an average of the A/F ratio. These measurments determine the short term fuel trims, and then the long term fuel trims are based on those numbers.
If the O2 hangs at rich or hangs at lean when the computer commands one or the other, it will set a code and typically stay in open loop, since it can't trust the O2 for accurate readings. So if you have a code for an O2 sensor malfunction, chances are the car is staying in open loop, meaning it should be driving just fine except for decreased fuel economy. Its unlikely that a failed O2 sensor would result in the car stuttering on a start, sounds like another issue. Pull the codes and let us know what you come up with.
Sorry I havent responded in a few days my dad had a heart attack sunday evening, I got ran over by a car and We have been dealing with a lot of crap. The car only does it when the A/C is on and you stop. If the A/C is off you never notice anything. Im gonna go out today and pull the codes.
08-20-2009 | 10:07 AM
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08-20-2009 | 02:29 PM
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08-20-2009 | 11:10 PM
#11
Sorry I havent responded in a few days my dad had a heart attack sunday evening, I got ran over by a car and We have been dealing with a lot of crap. The car only does it when the A/C is on and you stop. If the A/C is off you never notice anything. Im gonna go out today and pull the codes.
Let us know what you come up with when you have a chance.
