does this header have both 02 sensors or only 1
1168737
No the upstream (first) O2 Sensor should fit in this header. The downstream (second) sensor is already installed before your other catalytic converter. In order to prevent a check engine light I suggest moving the downstream sensor behind the second catalytic converter if you're buying this header.
1332010
There is only one sensor, Its an optical sensor, the "eye" senses the high and low level plus it has "smart" programming that will alert you of a problem. Theres in no redundant high level sensor. Theres good videos on youtube that shows you how it works. I absolutly love my Smart ATO!! Well woth the money!
1606634
Sensor 1 is bad. It's possible sensor 2 is as well but I would start with just sensor 1 because it could be reading "unknown" because the lack of a signal/data from sensor 1. You didn't specify if they were upsteam sensors (O2S11 & O2S12) or downstream after Cat (O2S21 & O2S22), but the upstream sensors are the most important cuz they control fuel trims & Air/Fuel Ratios. The downstream sensor are really only there to tell you if the Cat is good or not. I'm assuming you only have one Upstream & 1 Downstream sensor but some vehicles have more depending on exhaust setup. You may only see O2S11(Upstream 1) & O2S21(Downstream 1) or a combo of O2S11(Upstream 1), O2S12(Upstream 2) & 02S21(Downstream 1). Or even two Downstreams if you have true dual exhaust & not a Y-Pipe. You can tell if it's a upsteam or downstream sensor by the 4th character in the name coding. Example: 02S*1 * = 1:Upsteam, 2:Downstream. You can tell if it's a right or left sensor by the 5th character in the name coding. Example: 02S1* * = 1:one side, 2: other side. (Sorry can remember which one's right & which is left) Hope this helps.
1026702
Same sensor. Just changed out all four using four of these. Went from 9 codes down to 3.
640321
There are 2 oxygen sensors total. One before the catalytic converter and one after.
1406638
Mine came with one sensor. You can buy sensors separately. I bought two complete packages, because I wanted a receiver in my office (detached building) and home.
119652
I do not recall, however a friend of mine did have to replace a couple of sensors and they gave him the replacements immediately. Hope this helps.
1205131
This is one of the two sensors on a manual transmission 2002 tacoma. The other is a Denso 234-9003.
1236128
If you have a OBD reader that has SRS Info, it will tell you which sensor is bad. I replaced both on my '05 Silverado and the system reset and is working fine. Both of mine went out at the same time. But you need the reader to be sure.
1717000
post catalytic sensor, http://www.tacomaworld.com/forum/1st-gen-tacomas/75798-o2-sensors.html sensor 2.
1339858
One sensor... remember you need two if you want to monitor the standard set of tires on a motorcycle. :)
178194
This listing is for 2 sensors and the transducer. 45RFE takes a solenoid block. That transmission does not have individual solenoids. Thank you
656154
Two sensors, but they can both be mounted to the back wheel if desired. Not sure what you mean by year model
866002
There is only one sensor and it is inside the unit. I don't think this is meant to be outside.
1283269
They are two different sensors, i recommend going to the Denso website to get the two part numbers. The upstream fails more often and the downstream one is usually cheaper.
808154
One sensor. I imagine more than one could be used but check with the mfg first.
2044748
2 in front of catalytic converter in Y pipe & if dual exhaust, 2 behind which are a different part number...front & rear O2 sensors are NEVER the same...different readings before & after the converter are needed as well as different heats