got a code 44!!!
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From: Charlotte NC
Car: 92 Z28 Z03
Engine: 350
Transmission: 700-R4
Axle/Gears: 2.73 G80
but last time i had an o2 it was a code 13. plus i had it done like 2 years ago. so could the o2 put out another code? like the 44
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The typical failure mode for an O² is toward the lean end, so it is a possibility. This would be a "false" lean condition, since the ECM would think the mixture was lean when it truly isn't.
A DTC '13' means that the ECM is not getting even a minimal level signal from the oxygen sensor. A DTC 44 means that the ECM is getting some signal, but it is so low that it is presumed to be constantly lean (beyond the acceptable limits). This could mean a failed sensor or a poor electrical connection, including the all-important grounding of the exhaust pipe. Check the connections first, and make certain the exhaust system is grounded.
If you have a DMM you can test the sensor fairly easily. Remove the sensor and connect the voltmeter on a 2.0VDC scale. Hold the sensing element end in the flame of a propane torch while measuring voltage. The sensor should produce a signal of at least 0.75VDC within 60 seconds. Removing the flame should drop the sensor output to nearly 0VDC. This does not test the quality of the sensor, but will tell you if it is completely "dead" or not. A propane torch flame is nearly devoid of all oxygen and should produce a fairly high signal as a result, just like a very rich mixture.
If the sensor is O.K., there are other things to check that could be creating a "false" lean condition, including air leaks into the exhaust mainfolds. These can be from a failing AIR diverter, leaking AIR lines, rust holes in the 'Y' pipe, or exhaust gasket leaks.
Or you could truly have a lean condition caused by vacuum leaks, low fuel pressure/poor delivery, or a MAF that is over-reporting intake air flow.
Make sure the O² is reliable and the connections are good, then proceed with the diagnosis.
A DTC '13' means that the ECM is not getting even a minimal level signal from the oxygen sensor. A DTC 44 means that the ECM is getting some signal, but it is so low that it is presumed to be constantly lean (beyond the acceptable limits). This could mean a failed sensor or a poor electrical connection, including the all-important grounding of the exhaust pipe. Check the connections first, and make certain the exhaust system is grounded.
If you have a DMM you can test the sensor fairly easily. Remove the sensor and connect the voltmeter on a 2.0VDC scale. Hold the sensing element end in the flame of a propane torch while measuring voltage. The sensor should produce a signal of at least 0.75VDC within 60 seconds. Removing the flame should drop the sensor output to nearly 0VDC. This does not test the quality of the sensor, but will tell you if it is completely "dead" or not. A propane torch flame is nearly devoid of all oxygen and should produce a fairly high signal as a result, just like a very rich mixture.
If the sensor is O.K., there are other things to check that could be creating a "false" lean condition, including air leaks into the exhaust mainfolds. These can be from a failing AIR diverter, leaking AIR lines, rust holes in the 'Y' pipe, or exhaust gasket leaks.
Or you could truly have a lean condition caused by vacuum leaks, low fuel pressure/poor delivery, or a MAF that is over-reporting intake air flow.
Make sure the O² is reliable and the connections are good, then proceed with the diagnosis.
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