O2 Sensor Wiring Clarification & Swing Pattern on Right Bank
#1
O2 Sensor Wiring Clarification & Swing Pattern on Right Bank
Hi Guys and Gals,
not your typical O2 sensor issue. I have been trying to track down either an issue with the O2 sensor setup OR possibly another fueling issue. Reason for diagnostics is failed emissions with brand new cats.
First of all my RAVE pdf states:
1996
Pin 33 - LH PRE Sensor
Pin 34 - RH PRE Sensor
1997 - 1999
Pin 33 - RH PRE Sensor
Pin 34 - LH PRE Sensor
I have a 1996 BUT my sensors are setup like 1997+. If I swap the sensors around I get a full RICH on one bank and a full LEAN on another bank. So it would appear that it wants to be as 97+
----
Secondly I have an issue with the swing pattern on PIN 33 - currently RH PRE sensor. Pin 34 switches fast and very close to 0v and 5v. Pin 33 switches very slowly in comparison and is closer to 1v and 4v at its peaks. I have swapped left and right sensors and the results do no change banks.
I have a good 4.95v on both front plugs, a good 12v on both front plugs. Grounds show good with a maximum of .02v and good continuity to ground.
Either something strange is going on with the wiring somewhere on that bank OR for some strange reason that bank is being fueled differently.
Any suggestions???
not your typical O2 sensor issue. I have been trying to track down either an issue with the O2 sensor setup OR possibly another fueling issue. Reason for diagnostics is failed emissions with brand new cats.
First of all my RAVE pdf states:
1996
Pin 33 - LH PRE Sensor
Pin 34 - RH PRE Sensor
1997 - 1999
Pin 33 - RH PRE Sensor
Pin 34 - LH PRE Sensor
I have a 1996 BUT my sensors are setup like 1997+. If I swap the sensors around I get a full RICH on one bank and a full LEAN on another bank. So it would appear that it wants to be as 97+
----
Secondly I have an issue with the swing pattern on PIN 33 - currently RH PRE sensor. Pin 34 switches fast and very close to 0v and 5v. Pin 33 switches very slowly in comparison and is closer to 1v and 4v at its peaks. I have swapped left and right sensors and the results do no change banks.
I have a good 4.95v on both front plugs, a good 12v on both front plugs. Grounds show good with a maximum of .02v and good continuity to ground.
Either something strange is going on with the wiring somewhere on that bank OR for some strange reason that bank is being fueled differently.
Any suggestions???
#4
I don't know if it CAN be the ECU at this point. The ECU is sending the 5v reference and the sensor ground - it should be all down to the 02 sensor to do the switching/swing part of things.
The good bank with a DVM will go somthing like 4.9v 4.8v 0.1v 0.1v 4.9v
The other bank is like 4v 3.8v 3.6v 3.4v 3.2v 3v 2.8v 2.6v ....... and so on
graphing these in OBD2 shows the first as a nice "SAW Blade" and the second more like sea waves.
The good bank with a DVM will go somthing like 4.9v 4.8v 0.1v 0.1v 4.9v
The other bank is like 4v 3.8v 3.6v 3.4v 3.2v 3v 2.8v 2.6v ....... and so on
graphing these in OBD2 shows the first as a nice "SAW Blade" and the second more like sea waves.
#5
#6
Join Date: Mar 2010
Location: Pittsburgh PA suburbs.
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As I understand it, the O2 sensors provide an input to ECM do they not? And the ECM determines the fueling ratio or whatever the appropriate term is.
I have seen photos and reports of corrosion internal to the ECM and similar issues.
Apparently there is some voltage drop somewhere in the circuit or possibly degraded components which I think are limited to inside of the ECM if the sensors themselve are good. Unless there is a wire harness related issue.
My 97 was plagued with corrosion on electrical connection when I first bought it several years ago.
These are just my general observations from past experiences. By no means a
X-Spurt on such matters.
I have seen photos and reports of corrosion internal to the ECM and similar issues.
Apparently there is some voltage drop somewhere in the circuit or possibly degraded components which I think are limited to inside of the ECM if the sensors themselve are good. Unless there is a wire harness related issue.
My 97 was plagued with corrosion on electrical connection when I first bought it several years ago.
These are just my general observations from past experiences. By no means a
X-Spurt on such matters.
#7
#8
By far the most common used sensor is the Zirconia which is the one you talked about. Land Rover at the time decided to use Titania sensors. This is reason you cannot use the cheap "ebay" sensors on these vehicles even if they are both 4 wires.
Oxygen sensor - Wikipedia, the free encyclopedia
Oxygen sensor - Wikipedia, the free encyclopedia