About to start RB26, but second O2 is broken...

[technorb26]

Hi everybody,

what will happen if I start my Rb26 with the second O2 sensor completely disconnected? Is it going to run OK? Is the O2 just for low speed driveabilty feedback? Or it is absolutely needed, even to make the car drive slowly, idle, etc.?

Also, I found a pencil O2 sensor , used, with a Nissan logo on it, and i believe it is off a Sr20? Is that going to work on th RB26?

TIA

[Joe]

im not familiar with the RB26's o2 setup but one of 2 things will happen

1) you will run very rich and get bad gas mileage at cruise/off idle, if the GTR uses 2 o2 sensors like 1 per downpipe it now isnt getting an air fuel reading from one of the sensors so it has to always run in whats called open loop, not using the o2 for feedback and adjustments on the AF ratio. or it could substitute the other o2 sensor for both readings.

2) nothing, if it uses that second sensor to just monitor the effiencey of the catalytic converter. this second o2 sensor has nothing to do with AF control.

both will cause a check engine light, but you arent gonna damage anything for sure. i do now know wich way its done but im assuming its 1 o2 sensor per downpipe. i dont know what year RB26 you have or if it has a catalytic converter (i dobut it).

[technorb26]

It is the early R32 RB26. One sensor per turbo/O2 housing. I assume it will be rich?

[Ramius83]

Well, as with the Maximas, if one O2 sensor failed, it just caused bad gas mileage and a CEL.

The O2 sensors are monitored when the ECU is in open loop. The use of the O2 sensors is mostly used to monitor the condition of the exhaust gases. By this, the best air/fuel ratios are determined, and gas mileage falls within that use.

Whenever the car is in the warm-up stage and at WOT, the ECU enters closed loop. By this, the ECU does NOT monitor most of its sensors and runs on a pre-determined "rich" condition set within it's memory by the factory. When it sees that the engine has been warmed up and/or is not in WOT, it will then enter open loop and run the engine to the best fuel economy it can by monitoring its sensors.

I am sure that you can find a "generic" BOSCH O2 sensor here in the states to use. Just go to http://www.skylinesdownunder.com and see if you can find the part number for that O2 sensor. Then, just cross-reference that number here in the states to find it. I know that it will be BOSCH because since the mid 80s, Nissan has almost always used BOSCH as its maker for O2 sensors, and other little sensors here and there.

[technorb26]

Thanks, that is what I wanted to hear

Well, as with the Maximas, if one O2 sensor failed, it just caused bad gas mileage and a CEL.

The O2 sensors are monitored when the ECU is in open loop. The use of the O2 sensors is mostly used to monitor the condition of the exhaust gases. By this, the best air/fuel ratios are determined, and gas mileage falls within that use.

Whenever the car is in the warm-up stage and at WOT, the ECU enters closed loop. By this, the ECU does NOT monitor most of its sensors and runs on a pre-determined "rich" condition set within it's memory by the factory. When it sees that the engine has been warmed up and/or is not in WOT, it will then enter open loop and run the engine to the best fuel economy it can by monitoring its sensors.

I am sure that you can find a "generic" BOSCH O2 sensor here in the states to use. Just go to http://www.skylinesdownunder.com and see if you can find the part number for that O2 sensor. Then, just cross-reference that number here in the states to find it. I know that it will be BOSCH because since the mid 80s, Nissan has almost always used BOSCH as its m

aker for O2 sensors, and other little sensors here and there.

[Wulfgang]

Well, as with the Maximas, if one O2 sensor failed, it just caused bad gas mileage and a CEL.

The O2 sensors are monitored when the ECU is in open loop. The use of the O2 sensors is mostly used to monitor the condition of the exhaust gases. By this, the best air/fuel ratios are determined, and gas mileage falls within that use.

Whenever the car is in the warm-up stage and at WOT, the ECU enters closed loop. By this, the ECU does NOT monitor most of its sensors and runs on a pre-determined "rich" condition set within it's memory by the factory. When it sees that the engine has been warmed up and/or is not in WOT, it will then enter open loop and run the engine to the best fuel economy it can by monitoring its sensors.

I am sure that you can find a "generic" BOSCH O2 sensor here in the states to use. Just go to http://www.skylinesdownunder.com and see if you can find the part number for that O2 sensor. Then, just cross-reference that number here in the states to find it. I know that it will be BOSCH because since the mid 80s, Nissan has almost always used BOSCH as its maker for O2 sensors, and other little sensors here and there.

Heh, you switched "open loop" with "closed loop."

And like other people have said, if it is the 2nd O2 sensor and is downstream of the 1st O2 sensor (behind the cat), then don't even worry about replacing it, since it is only used to check the condition of the cat.

However, if there are upstream sensors (one per turbo) and you are talking about one of those, then yes, you can use any narrowband O2 sensor that fits. Try to get one that matches the other one so that both are either heated or unheated. (The heated ones have three wires.)

[technorb26]

Heh, you switched "open loop" with "closed loop."

And like other people have said, if it is the 2nd O2 sensor and is downstream of the 1st O2 sensor (behind the cat), then don't even worry about replacing it, since it is only used to check the condition of the cat.

However, if there are upstream sensors (one per turbo) and you are talking about one of those, then yes, you can use any narrowband O2 sensor that fits. Try to get one that matches the other one so that both are either heated or unheated. (The heated ones have three wires.)

Yes, both are upstream, one per turbo, just like a 300zx z32. I found a pencil style Nissan narrowband heated sensor, I guess I will use that one.

And when the AEM EMS comes out, I will just disregard both.

[Ramius83]

Heh, you switched "open loop" with "closed loop."

And like other people have said, if it is the 2nd O2 sensor and is downstream of the 1st O2 sensor (behind the cat), then don't even worry about replacing it, since it is only used to check the condition of the cat.

However, if there are upstream sensors (one per turbo) and you are talking about one of those, then yes, you can use any narrowband O2 sensor that fits. Try to get one that matches the other one so that both are either heated or unheated. (The heated ones have three wires.)

Yeah, I went back on last night and saw that I had switched it. I wasn't in the best mood last night with this stupid flu I have....

[ibzbro]

here are the numbers for the o2 sensors if you need them

22690-05u2122690-05u22