Which side for which 02 sensor?
Thread Starter
Safety Car
Joined: Jul 2005
Posts: 4,275
Likes: 4
From: Vancouver WA
Which side for which 02 sensor?
I want to make sure I am putting these in right.
For the front 02 sensors, does the driver side sensor go to the driver side header.
But the rears cross?
For the front 02 sensors, does the driver side sensor go to the driver side header.
But the rears cross?
Thread Starter
Safety Car
Joined: Jul 2005
Posts: 4,275
Likes: 4
From: Vancouver WA
Melting Slicks
Joined: Jul 2005
Posts: 2,586
Likes: 2
From: Bardstown Kentucky
The fuel trims go CRAZY and the car will fight itself to stay running.
Thread Starter
Safety Car
Joined: Jul 2005
Posts: 4,275
Likes: 4
From: Vancouver WA
I'm not sure what the rears will do if they are crossed, but if you cross your fronts, your fuel trims will be out of whack because the PCM will be adding or subtracting fuel to the wrong side. Since it will be adjusting the wrong injectors, there will be no change, and the PCM will keep adding or subracting.
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Burning Brakes
Joined: Jun 2006
Posts: 933
Likes: 0
From: St. Paul MN
So there is actually a different part number for the right and left side 02 sensor? I swear that they were identical. The wires were the same color, etc. They both plugged in fine.
My car is bucking a little at low rpm (1500 rpm and under) but I attributed that to the fact that I just installed new heads, cam (228/230 .571/.573 112lsa), intake, and headers. Either that or I damaged a plug and/or spark plug wire (I had to pull a few out by the wire as opposed to the boot to get them out).
So is there a part number on the o2 sensor? If I bought a set from the dealer how would I know if I received the correct one?
My car is bucking a little at low rpm (1500 rpm and under) but I attributed that to the fact that I just installed new heads, cam (228/230 .571/.573 112lsa), intake, and headers. Either that or I damaged a plug and/or spark plug wire (I had to pull a few out by the wire as opposed to the boot to get them out).
So is there a part number on the o2 sensor? If I bought a set from the dealer how would I know if I received the correct one?
Melting Slicks
Joined: Jul 2005
Posts: 2,586
Likes: 2
From: Bardstown Kentucky
No the sensors are the same... but what happens is this
The Computer senses that the Pass. side is lean, but actually since the wires are reversed its the drivers side thats lean. So the Computer says add fuel to the passenger side, well since the wires are reversed the fuel goes to the wrong place. This just keeps happening until finally one side is so fat and one is so lean the car will sputter and carry on.
The Computer senses that the Pass. side is lean, but actually since the wires are reversed its the drivers side thats lean. So the Computer says add fuel to the passenger side, well since the wires are reversed the fuel goes to the wrong place. This just keeps happening until finally one side is so fat and one is so lean the car will sputter and carry on.
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
No the sensors are the same... but what happens is this
The Computer senses that the Pass. side is lean, but actually since the wires are reversed its the drivers side thats lean. So the Computer says add fuel to the passenger side, well since the wires are reversed the fuel goes to the wrong place. This just keeps happening until finally one side is so fat and one is so lean the car will sputter and carry on.
The Computer senses that the Pass. side is lean, but actually since the wires are reversed its the drivers side thats lean. So the Computer says add fuel to the passenger side, well since the wires are reversed the fuel goes to the wrong place. This just keeps happening until finally one side is so fat and one is so lean the car will sputter and carry on.
EXCEPT for ther rear sensors (which the OP also asked about). The rear sensors are not used for AFR adjustment. No driveability issues arise from mixing up the L/R rear sensors.
The only caveat is if one of the "mixed up" rears fails; the error code will point to the wrong one.
Melting Slicks
Joined: Jul 2005
Posts: 2,586
Likes: 2
From: Bardstown Kentucky
EXCEPT for ther rear sensors (which the OP also asked about). The rear sensors are not used for AFR adjustment. No driveability issues arise from mixing up the L/R rear sensors.
The only caveat is if one of the "mixed up" rears fails; the error code will point to the wrong one.
The only caveat is if one of the "mixed up" rears fails; the error code will point to the wrong one.
I just didnt know anyone ran the rear O2's anymore.. I have been in KY too long!
Melting Slicks
Joined: Jul 2005
Posts: 2,586
Likes: 2
From: Bardstown Kentucky
EXCEPT for ther rear sensors (which the OP also asked about). The rear sensors are not used for AFR adjustment. No driveability issues arise from mixing up the L/R rear sensors.
The only caveat is if one of the "mixed up" rears fails; the error code will point to the wrong one.
The only caveat is if one of the "mixed up" rears fails; the error code will point to the wrong one.
For the front 02 sensors, does the driver side sensor go to the driver side header.
Burning Brakes
Joined: Jun 2006
Posts: 933
Likes: 0
From: St. Paul MN
No the sensors are the same... but what happens is this
The Computer senses that the Pass. side is lean, but actually since the wires are reversed its the drivers side thats lean. So the Computer says add fuel to the passenger side, well since the wires are reversed the fuel goes to the wrong place. This just keeps happening until finally one side is so fat and one is so lean the car will sputter and carry on.
The Computer senses that the Pass. side is lean, but actually since the wires are reversed its the drivers side thats lean. So the Computer says add fuel to the passenger side, well since the wires are reversed the fuel goes to the wrong place. This just keeps happening until finally one side is so fat and one is so lean the car will sputter and carry on.
Melting Slicks
Joined: Jul 2005
Posts: 2,586
Likes: 2
From: Bardstown Kentucky
if you plug the passenger side sensor into the drivers side harness and vice versa.... it throws the readings off because the pcm is getting info for the passenger side that is actually in the drivers side manifold.
Burning Brakes
Joined: Jun 2006
Posts: 933
Likes: 0
From: St. Paul MN
I thought we determined that both sensors are identical.If both O2 sensors are identical and I the wiring harness hasn't been moved how could one possibly get this mixed up?
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 77
From: Forney Texas
The 02 sensors are the same part number. One harness is for the drivers side and one for the passenger. The PCM uses the feedback from these sensors to make fuel calculations. If they are on the wrong side, then the PCM will be making compensation for the wrong side of the motor and not see a desired response from that sensor. It will then continue to increase the compensation until problems occur. Lets say the sensors are reversed and the feedback from the drivers' bank sensor shows lean but it's actually on the passenger side. The PCM will increase the pulse to the injectors on the drivers side. It will see no result and will continue to do so until the pulse width is increased to the maximum allowed. At the same time, the passenger side sees the increase in fuel and thinks that it needs to lean out, so it does so until it reaches the maximum allowed compensation. This will be a problem!!
Drifting
Joined: May 2005
Posts: 1,590
Likes: 1
From: Littleton Colorado
The front O2s are right next to each other and overlap. Its very easy to mix them up. You should install one at a time and make sure the first is going to/from the right place, but even then its easy to forget that the front does not cross or which side you are working on. It seems really simple, but its easy to get mixed up with the orientation of the sensors and headers.
Its a common mistake and most who do it can swear they did not mess it up, until they look again.
Rough running after a LT install is almost always crossed O2s.
Burning Brakes
Joined: Jun 2006
Posts: 933
Likes: 0
From: St. Paul MN
I must be working on a different car. 
Are the 98's different than others? The female sockets to which I plug my 02 sensors in to are a good three feet apart and are attached to the undercarriage. The wire coming off of the 02 sensor is about 6 inches long and couldn't possibly reach to the other side of the car. So if the 02 sensor is the same part (which includes the male socket) then there should be no way I could have them mixed up correct?
Are the 98's different than others? The female sockets to which I plug my 02 sensors in to are a good three feet apart and are attached to the undercarriage. The wire coming off of the 02 sensor is about 6 inches long and couldn't possibly reach to the other side of the car. So if the 02 sensor is the same part (which includes the male socket) then there should be no way I could have them mixed up correct?