02s Suddenly Drop From 950+ mV to Less than 100 mV at WOT
04-10-2005, 12:46 AM
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02s Suddenly Drop From 950+ mV to Less than 100 mV at WOT A few days ago I reported that I was having a problem with my car cutting out at high RPM during WOT; it was almost as if the car was hitting the rev-limiter. I've been looking at my log file, and I discovered that my 02s are suddenly dropping dramatically at WOT. They're dropping at exactly the same time the engine starts "missing."
While this is happening, the injector pulse width is falling from 19+ to less than 1 (usually 0.5). Usually, both banks fall equally, but there are several instances when B1 is at ~19 and B2 is at ~0.5.
Here's an example of this from my log (RPM, TP, Timing, 02B1, 02B2, Inj. B1, Inj. B2)...
The entire log is available here.
Is this the result of a bad 02 sensor or 02 sensor connection? Or is something else causing this?
Interestingly, it seems to happen only in first and second gear.
Thanks,
Josh
While this is happening, the injector pulse width is falling from 19+ to less than 1 (usually 0.5). Usually, both banks fall equally, but there are several instances when B1 is at ~19 and B2 is at ~0.5.
Here's an example of this from my log (RPM, TP, Timing, 02B1, 02B2, Inj. B1, Inj. B2)...
Code:
6173 100 28.5 959 938 19.2 19.3 6150 100 28.5 82 464 19.5 19.4 6369 100 28.5 78 87 0.5 0.5 6353 100 28.5 378 113 18.9 0.5 6140 0 37.5 964 951 10.8 4.9 6017 0 37.5 90 898 929 0.5 5771 0 37.5 838 885 2.1 2 5511 0 37.5 760 799 2.1 1.9 5196 29 31.5 690 790 2 1.9 5296 100 28.5 968 946 21.5 20.8
Is this the result of a bad 02 sensor or 02 sensor connection? Or is something else causing this?
Interestingly, it seems to happen only in first and second gear.
Thanks,
Josh
04-10-2005, 04:54 AM
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Originally Posted by Josh
A few days ago I reported that I was having a problem with my car cutting out at high RPM during WOT; it was almost as if the car was hitting the rev-limiter. I've been looking at my log file, and I discovered that my 02s are suddenly dropping dramatically at WOT. They're dropping at exactly the same time the engine starts "missing."
While this is happening, the injector pulse width is falling from 19+ to less than 1 (usually 0.5). Usually, both banks fall equally, but there are several instances when B1 is at ~19 and B2 is at ~0.5.
Here's an example of this from my log (RPM, TP, Timing, 02B1, 02B2, Inj. B1, Inj. B2)...
The entire log is available here.
Is this the result of a bad 02 sensor or 02 sensor connection? Or is something else causing this?
Interestingly, it seems to happen only in first and second gear.
Thanks,
Josh
While this is happening, the injector pulse width is falling from 19+ to less than 1 (usually 0.5). Usually, both banks fall equally, but there are several instances when B1 is at ~19 and B2 is at ~0.5.
Here's an example of this from my log (RPM, TP, Timing, 02B1, 02B2, Inj. B1, Inj. B2)...
Code:
6173 100 28.5 959 938 19.2 19.3 6150 100 28.5 82 464 19.5 19.4 6369 100 28.5 78 87 0.5 0.5 6353 100 28.5 378 113 18.9 0.5 6140 0 37.5 964 951 10.8 4.9 6017 0 37.5 90 898 929 0.5 5771 0 37.5 838 885 2.1 2 5511 0 37.5 760 799 2.1 1.9 5196 29 31.5 690 790 2 1.9 5296 100 28.5 968 946 21.5 20.8
Is this the result of a bad 02 sensor or 02 sensor connection? Or is something else causing this?
Interestingly, it seems to happen only in first and second gear.
Thanks,
Josh
04-10-2005, 07:04 AM
#4
I'd hang a fuel pressure gauge on it where you an see the indicator and re-test.
Ghetto setup is to duct-tape the indicator to the outside of your windshield. You just need one good WOT blast to see if the needle drops as the revs climb.
Ghetto setup is to duct-tape the indicator to the outside of your windshield. You just need one good WOT blast to see if the needle drops as the revs climb.
04-10-2005, 08:02 AM
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Your rev limiter can be different in different gears. Who tuned it, and can you look at the tune. That does not look like an accident. It looks like you actually did hit a rev limiter.
04-10-2005, 09:12 AM
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The rev-limiter is at 7000 in every gear. I tuned it myself and have triple checked it since I first discovered this was happening.
Josh
Josh
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04-10-2005, 11:29 AM
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Originally Posted by Josh
The rev-limiter is at 7000 in every gear. I tuned it myself and have triple checked it since I first discovered this was happening.
Josh
Josh
