02 sensor?
10-10-2006, 09:48 PM
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02 sensor? just bought an 01 ss and it had a check eng light it was the 02 sensors on the driver side replaced both and now it says all 4 02s are bad! hit a hard bump and the light shut of and now it just came back on any ideas!
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10-25-2006, 12:09 PM
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Hai,
The 02 sensor is right at the entrance of the tube that the open air filter connects to...some say that open air cone filter sucks in too much for the 02 sensor to handle causing the failure...
That's not the Oxygen (O2) sensor, that is the Mass Air Flow (MAF) meter. The oxygen sensors are located in the exhaust manifolds and in the exhaust pipes just downstream of the front catalytic converters (total of 4 O2 sensors).
Anyway, there is no way an air filter change is going to affect the O2 sensors. There is a slim possibility that an oiled type air filter could contaminate the heated wires in the MAF, but this is a very remote possibility. If that is the case, the MAF can be cleaned with some spray type carb cleaner.
The main problem I see with these aftermarket airfilter assemblies that replace the stock airbox is that they don't exactly match the cross sectional area of the pipe where the MAF sensor mounts. The air inlet tube is about 3" in diameter except where the MAF sensor is mounted and there it is compressed about 3/4" at the top where the sensor bolts on. The MAF sensor just measures air temperature and air velocity and then the computer calculates the mass of air flowing into the engine based on the cross sectional area of the pipe at that point where velocity is measured. If you go and enlarge this pipe at that point, the computer has no way of knowing that and will calculate mass air flow based on the smaller pipe when in reality you will likely have more air flowing past the sensor than previously. This could result in a lean condition until the computer remaps the fuel curves (using input from the oxygen sensors) for a given throttle position (assuming it has the capability to compenstate for that amount of increased air flow). This remapping evolution takes some time though. This is one reason it is a good idea to reset the ECU during mods like this (just disconnect a batter terminal for 30 minutes or so) which resets the fuel curves back to default values which are typically richer than normal. These richer fuel values allow the truck to continue to run without damage in the event of an oxygen sensor or other sensor failure. Once the ECU is reset, it will begin to "re-learn" the optimum fuel settings based on new input from the available sensors.
The 02 sensor is right at the entrance of the tube that the open air filter connects to...some say that open air cone filter sucks in too much for the 02 sensor to handle causing the failure...
That's not the Oxygen (O2) sensor, that is the Mass Air Flow (MAF) meter. The oxygen sensors are located in the exhaust manifolds and in the exhaust pipes just downstream of the front catalytic converters (total of 4 O2 sensors).
Anyway, there is no way an air filter change is going to affect the O2 sensors. There is a slim possibility that an oiled type air filter could contaminate the heated wires in the MAF, but this is a very remote possibility. If that is the case, the MAF can be cleaned with some spray type carb cleaner.
The main problem I see with these aftermarket airfilter assemblies that replace the stock airbox is that they don't exactly match the cross sectional area of the pipe where the MAF sensor mounts. The air inlet tube is about 3" in diameter except where the MAF sensor is mounted and there it is compressed about 3/4" at the top where the sensor bolts on. The MAF sensor just measures air temperature and air velocity and then the computer calculates the mass of air flowing into the engine based on the cross sectional area of the pipe at that point where velocity is measured. If you go and enlarge this pipe at that point, the computer has no way of knowing that and will calculate mass air flow based on the smaller pipe when in reality you will likely have more air flowing past the sensor than previously. This could result in a lean condition until the computer remaps the fuel curves (using input from the oxygen sensors) for a given throttle position (assuming it has the capability to compenstate for that amount of increased air flow). This remapping evolution takes some time though. This is one reason it is a good idea to reset the ECU during mods like this (just disconnect a batter terminal for 30 minutes or so) which resets the fuel curves back to default values which are typically richer than normal. These richer fuel values allow the truck to continue to run without damage in the event of an oxygen sensor or other sensor failure. Once the ECU is reset, it will begin to "re-learn" the optimum fuel settings based on new input from the available sensors.
10-25-2006, 03:15 PM
#11
Originally Posted by johnfedrer
Hai,
The 02 sensor is right at the entrance of the tube that the open air filter connects to...some say that open air cone filter sucks in too much for the 02 sensor to handle causing the failure...
That's not the Oxygen (O2) sensor, that is the Mass Air Flow (MAF) meter. The oxygen sensors are located in the exhaust manifolds and in the exhaust pipes just downstream of the front catalytic converters (total of 4 O2 sensors).
Anyway, there is no way an air filter change is going to affect the O2 sensors. There is a slim possibility that an oiled type air filter could contaminate the heated wires in the MAF, but this is a very remote possibility. If that is the case, the MAF can be cleaned with some spray type carb cleaner.
The main problem I see with these aftermarket airfilter assemblies that replace the stock airbox is that they don't exactly match the cross sectional area of the pipe where the MAF sensor mounts. The air inlet tube is about 3" in diameter except where the MAF sensor is mounted and there it is compressed about 3/4" at the top where the sensor bolts on. The MAF sensor just measures air temperature and air velocity and then the computer calculates the mass of air flowing into the engine based on the cross sectional area of the pipe at that point where velocity is measured. If you go and enlarge this pipe at that point, the computer has no way of knowing that and will calculate mass air flow based on the smaller pipe when in reality you will likely have more air flowing past the sensor than previously. This could result in a lean condition until the computer remaps the fuel curves (using input from the oxygen sensors) for a given throttle position (assuming it has the capability to compenstate for that amount of increased air flow). This remapping evolution takes some time though. This is one reason it is a good idea to reset the ECU during mods like this (just disconnect a batter terminal for 30 minutes or so) which resets the fuel curves back to default values which are typically richer than normal. These richer fuel values allow the truck to continue to run without damage in the event of an oxygen sensor or other sensor failure. Once the ECU is reset, it will begin to "re-learn" the optimum fuel settings based on new input from the available sensors.
The 02 sensor is right at the entrance of the tube that the open air filter connects to...some say that open air cone filter sucks in too much for the 02 sensor to handle causing the failure...
That's not the Oxygen (O2) sensor, that is the Mass Air Flow (MAF) meter. The oxygen sensors are located in the exhaust manifolds and in the exhaust pipes just downstream of the front catalytic converters (total of 4 O2 sensors).
Anyway, there is no way an air filter change is going to affect the O2 sensors. There is a slim possibility that an oiled type air filter could contaminate the heated wires in the MAF, but this is a very remote possibility. If that is the case, the MAF can be cleaned with some spray type carb cleaner.
The main problem I see with these aftermarket airfilter assemblies that replace the stock airbox is that they don't exactly match the cross sectional area of the pipe where the MAF sensor mounts. The air inlet tube is about 3" in diameter except where the MAF sensor is mounted and there it is compressed about 3/4" at the top where the sensor bolts on. The MAF sensor just measures air temperature and air velocity and then the computer calculates the mass of air flowing into the engine based on the cross sectional area of the pipe at that point where velocity is measured. If you go and enlarge this pipe at that point, the computer has no way of knowing that and will calculate mass air flow based on the smaller pipe when in reality you will likely have more air flowing past the sensor than previously. This could result in a lean condition until the computer remaps the fuel curves (using input from the oxygen sensors) for a given throttle position (assuming it has the capability to compenstate for that amount of increased air flow). This remapping evolution takes some time though. This is one reason it is a good idea to reset the ECU during mods like this (just disconnect a batter terminal for 30 minutes or so) which resets the fuel curves back to default values which are typically richer than normal. These richer fuel values allow the truck to continue to run without damage in the event of an oxygen sensor or other sensor failure. Once the ECU is reset, it will begin to "re-learn" the optimum fuel settings based on new input from the available sensors.
If you hit a bump and get an 02 code, check your ground wires. The PCM wiring harness has 3 grounds on the back of the drivers side head.
