Diagnoses of O2s being lazy
04-14-2009, 04:47 PM
#1
Diagnoses of O2s being lazy
Hi gang,
So Haynes' O2 checking states to check the voltage readout of warmed up sensors from the center lead to a good ground. Good operating O2s will fluctuate from the range of 100mv to 900mv, reading from one extreme to the other in quick order...
The rear is only different in how fast it reads it out the fluctuation. It's a little slower.
The second test is to test the resistance of the two heater leads (mine are white, pin1 and pin3) and should readout 2-4ohms.
Mine pass the first test, and are about 2 ohms off for the heater, reading about 6ohms.
If anyone is of the electrical mindset, my question is: Between the two tests, which, if it's either one or both, would be more of a diagnosis of a "lazy" sensor?
Cheers to you Maxima freaks
-t
So Haynes' O2 checking states to check the voltage readout of warmed up sensors from the center lead to a good ground. Good operating O2s will fluctuate from the range of 100mv to 900mv, reading from one extreme to the other in quick order...
The rear is only different in how fast it reads it out the fluctuation. It's a little slower.
The second test is to test the resistance of the two heater leads (mine are white, pin1 and pin3) and should readout 2-4ohms.
Mine pass the first test, and are about 2 ohms off for the heater, reading about 6ohms.
If anyone is of the electrical mindset, my question is: Between the two tests, which, if it's either one or both, would be more of a diagnosis of a "lazy" sensor?
Cheers to you Maxima freaks
-t
04-14-2009, 06:29 PM
#3
Junior Member
Join Date: Jan 2007
Location: Houston TX
Posts: 15
Any value in that "Diagnostic Test Mode II" in the Factory Service Manual? I was thinking about trying that next weekend in my search for intermittent stall problems:
Turn ECU screw clockwise.
Wait 2 seconds
Turn counter clockwise.
Start car and warm up.
check engine light goes on when lean in closed loop
check engine light goes off when rich in closed loop
Do the screw turn / 2 second thing again and it switches from left bank O2 sensor to right bank.
Turn ECU screw clockwise.
Wait 2 seconds
Turn counter clockwise.
Start car and warm up.
check engine light goes on when lean in closed loop
check engine light goes off when rich in closed loop
Do the screw turn / 2 second thing again and it switches from left bank O2 sensor to right bank.
04-14-2009, 06:30 PM
#4
Any value in that "Diagnostic Test Mode II" in the Factory Service Manual? I was thinking about trying that next weekend in my search for intermittent stall problems:
Turn ECU screw clockwise.
Wait 2 seconds
Turn counter clockwise.
Start car and warm up.
check engine light goes on when lean in closed loop
check engine light goes off when rich in closed loop
Do the screw turn / 2 second thing again and it switches from left bank O2 sensor to right bank.
Turn ECU screw clockwise.
Wait 2 seconds
Turn counter clockwise.
Start car and warm up.
check engine light goes on when lean in closed loop
check engine light goes off when rich in closed loop
Do the screw turn / 2 second thing again and it switches from left bank O2 sensor to right bank.
04-14-2009, 07:54 PM
#5
Any value in that "Diagnostic Test Mode II" in the Factory Service Manual? I was thinking about trying that next weekend in my search for intermittent stall problems:
Turn ECU screw clockwise.
Wait 2 seconds
Turn counter clockwise.
Start car and warm up.
check engine light goes on when lean in closed loop
check engine light goes off when rich in closed loop
Do the screw turn / 2 second thing again and it switches from left bank O2 sensor to right bank.
Turn ECU screw clockwise.
Wait 2 seconds
Turn counter clockwise.
Start car and warm up.
check engine light goes on when lean in closed loop
check engine light goes off when rich in closed loop
Do the screw turn / 2 second thing again and it switches from left bank O2 sensor to right bank.
Thanks Pmohr for consistent feedback. I've got consult and obdii cables and software on the way.
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